LonKing Repair Manual [PDF]

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Table of contents

Table of contents

Chapter 1 Safety precautions..................................................................................................................[1] Chapter 2 Diagrams and parameters of complete-loader............................................................... [3] Chapter 3 Maintenance points of complete-loader........................................................................... [7] Chapter 4 Standard Data Sheet............................................................................................................ [12] Chapter 5 Troubleshooting....................................................................................................................[21] 5-1 Torque converter and gearbox system.........................................................................................[22] 5-2 Drive axle system.............................................................................................................................[39] 5-3 Working hydraulic system...............................................................................................................[42] 5-4

Pilot control system................................................................................................................................... [48]

5-5 Steering hydraulic system.............................................................................................................. [54] 5-6 Foot brake system........................................................................................................................... [58] 5-7 Electric system................................................................................................................................. [61] Chapter 6 Main Parts..................................................................................................................................[67] Section 1

Hydraulic torque converter................................................................................................ [68]

6-1-1 Structure and Functions.................................................................................................... [68] 6-1-2 Testing and Adjustment.....................................................................................................[71] 6-1-3 Dismounting and Installation............................................................................................ [72] 6-1-4 Disassembly and Repair................................................................................................... [73] Section 2

Gearbox .............................................................................................................................. [86]

6-2-1 Structure and Functions.................................................................................................... [86] 6-2-2 Testing and Adjustment.....................................................................................................[87] 6-2-3 Dismounting and Installation............................................................................................ [88] 6-2-4 Disassembly and Repair................................................................................................... [94] Section 3

Drive axle........................................................................................................................... [120]

6-3-1 Structure and Functions..................................................................................................[120] 6-3-2 Dismounting and Installation.......................................................................................... [121] 6-3-3 Disassembly and Repair................................................................................................. [123] Section 4

Air brake valve assembly.................................................................................................[144]

6-4-1 Structure and Functions..................................................................................................[144] 6-4-2 Dismounting and Installation.......................................................................................... [145] 6-4-3 Disassembly and Repair................................................................................................. [146] Section 5

Combination valve of oil-water separator (SH380D) .................................................[155]

6-5-1 Structure and Functions..................................................................................................[155] 6-5-2 Dismounting and Installation.......................................................................................... [156] 1

Table of contents

Section 6

Booster pump.................................................................................................................... [157]

6-6-1 Structure and Functions..................................................................................................[157] 6-6-2 Testing and Adjustment.................................................................................................. [157] 6-6-3 Dismounting and Installation.......................................................................................... [158] 6-6-4 Disassembly and Repair................................................................................................. [159] Section 7

Brake caliper (brake system).......................................................................................... [171]

6-7-1 Structure and Functions..................................................................................................[171] 6-7-2 Testing and Adjustment.................................................................................................. [171] 6-7-3 Dismounting and Installation.......................................................................................... [171] 6-7-4 Disassembly and Repair................................................................................................. [171] Section 8

Working pump................................................................................................................... [178]

6-8-1 Structure and Functions..................................................................................................[178] 6-8-2 Dismounting and Installation.......................................................................................... [178] 6-8-3 Disassembly and Repair................................................................................................. [179] Section 9

Distribution valve...............................................................................................................[192]

6-9-1 Structure and Functions..................................................................................................[192] 6-9-2 Testing and Adjustment.................................................................................................. [193] 6-9-3 Dismounting and Installation.......................................................................................... [195] 6-9-4 Disassembly and Repair................................................................................................. [196] Section 10

Lift arm cylinder...............................................................................................................[206]

6-10-1 Structure and Functions................................................................................................[206] 6-10-2 Dismounting and Installation........................................................................................ [206] 6-10-3 Disassembly and Repair...............................................................................................[207] Section 11

Bucket cylinder................................................................................................................[214]

6-11-1 Structure and Functions................................................................................................[214] 6-11-2 Dismounting and Installation........................................................................................ [214] 6-11-3 Disassembly and Repair...............................................................................................[215] Section 12

Priority valve.................................................................................................................... [222]

6-12-1 Structure and Functions................................................................................................[222] 6-12-2 Dismounting and Installation........................................................................................ [222] 6-12-3 Disassembly and Repair...............................................................................................[224] Section 13

Steering gear................................................................................................................... [229]

6-13-1 Structure and Functions................................................................................................[229] 6-13-2 Dismounting and Installation........................................................................................ [229] 6-13-3 Disassembly and Repair...............................................................................................[231] Section 14

Steering cylinder ........................................................................................................... [247] 2

Table of contents

6-14-1 Structure and Functions................................................................................................[247] 6-14-2 Dismounting and Installation........................................................................................ [247] 6-14-3 Disassembly and Repair...............................................................................................[248] Section 15

Working hydraulic oil cooler.......................................................................................... [249]

6-15-1 Structure and Functions................................................................................................[249] 6-15-2 Testing and Adjustment................................................................................................ [249] 6-15-3 Dismounting and Installation........................................................................................ [251] Section 16

Air conditioning system..................................................................................................[253]

6-16-1 Structure and Functions................................................................................................[253] 6-16-2 Testing and Adjustment................................................................................................ [254] 6-16-3

Dismounting and Installation............................................................................................... [258]

Chapter 7 Hydraulic Schematic Diagram........................................................................................... [261] Chapter 8 Electrical Schematic Diagram............................................................................................[263]

3

Table of contents

4

Preface

Preface In order to enable distributors and repair service centers to know more about Lonking CDM835E I.00I loader, we have compiled this Repair Manual for CDM835E I.00I Wheel Loader and provide it to Lonking’s overseas agents and repair service centers. This Manual emphasizes the introduction of structure and functions, test and adjustment, installation and disassembly, dismounting and repair, troubleshooting, etc., and aims to provide the basic knowledge about repair service. The factors like difference of product sales regions, different environmental conditions, working conditions and operating skills and timeliness of daily maintenance will affect the operating status of loader. This Manual is based on the information available at the time of compilation, so it may not cover all the possible situations. We hope that during the use of this Manual, distributors and repair service centers may feed back their opinions and suggestions on a timely basis so that we will be able to make improvement in the next edition. Prior to repairing a loader, please carefully read and understand the safety precautions and make repairs in full accordance with safety instructions. Incorrect disassembly, installation and repairing are dangerous and may lead to injury or death. The pressures of some hydraulic components requiring parameters setting have been set at the time when the loader is shipped out of Lonking’s factory. If such components need repairing, in principle, the entire assembly shall be replaced (whether this Manual has introduced the dismounting and commissioning process or not) If an assembly is not available, only after the written consent of Lonking and component manufacturers has been obtained can these components be dismounted and repaired, and repairing entities shall be responsible for the quality and safety of these components after disassembly, installation and adjustment. We are making continuous effort to improve our products. We reserve the right to change the parameters and configurations of the loader. In addition, the contents of this Manual are subject to change without notice. The technical parameters mentioned in this Manual shall not be used as the basis for delivery and acceptance. This Manual is its first edition. Lonking Holdings Limited April 30, 2013

5

6

Chapter 1 Safety precautions

Chapter 1 Safety precautions I. Safety precautions before repair/maintenance 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16.

Flat and solid ground or special site shall be selected as the repair/maintenance site, which shall be far away from operating machines and personnel; Unauthorized personnel are not allowed to stay close to machines; When the gear is at neutral position, the bucket shall be placed on the ground horizontally. The pilot control rod shall be returned to its original position, and the hand brake shall be pulled up; The electric lock on the direction pillar shall be turned to the “OFF” position and the startup key shall be removed. The master power switch shall be cut off. In order to prevent short circuit, the storage battery shall be removed if necessary; A plate of “do not operate” shall be placed next to the master power switch to inform others that the machine is under maintenance; The parking brake shall be pushed down and a wedge block shall be placed before the front wheel or the rear wheel; The brake pedal shall be stepped down repeatedly to release all the pressure in the braking system; The pilot control rod shall be moved in full range to release all the pressure in the working device hydraulic system. The lift arm control lever and bucket control lever shall be placed at the “HOLD” position. The steering wheel shall be turned left and right for several times to release the pressure in the steering system. The wheel rims of four tires shall be fixed tightly in the grooves and the tire pressure shall be within the specified scope; The water or antifreeze fluid in the water tank shall be released if necessary, and it shall be done carefully not to burn hand, face or skin of other parts; In case any oil storage container or relevant oil-way is to be disassembled, the hydraulic oil or fuel oil shall be released first and contained in proper containers; All the fluid shall be disposed according to local laws and regulations; The front and rear chassis fixing rods shall be assembled properly to avoid injury or death caused by sway of machine. Upon the completion of repair/maintenance, the front and rear chassis fixing rods shall be released before the startup of machine. The rods shall be fixed at their storage places, otherwise the steering of machine will be affected.

II. Safety precautions during repair/maintenance 1. 2. 3. 4. 5. 6. 7.

8.

During the complete-machine repair/maintenance, a maintenance sign shall be set to prevent irrelevant personnel from staying close to the repair/maintenance site; The oil temperature shall be confirmed to be cool before any components or pipes are to be disassembled. Only after the engine is shut down and the oil filing cover is cooled to be touchable can the oil filling cover be removed. Failure around the engine shall be repaired after water and gas pipes, silencers, exhaust pipes, engine body, etc. cool down to prevent the hand or skin from being burnt； Special tools shall be used during disassembly of screws or fastening of components. Utilization of self-made tools is prohibited. The repairer shall start to conduct repair after steadying his body to prevent slipping. Large scope repair shall be conducted according to the following disassembly sequence: pipe, line – hood – cab – hydraulic component and pipe – bucket – lift arm – water tank – transmission shaft–gearbox-torque converter assembly of engine – frame assembly – drive axle – tire; Slings for lifting loads and lifting equipment with safety parameter higher than 1.5 shall be selected according to the component weight reference table During lifting, the hang-point shall be chosen first, and then the assembly hole on the component shall be chosen. The lifting shall be conducted on the front-rear and left-right symmetric basis. The lifting hook shall have separation prevention device. Standing under lifted goods is prohibited. The disassembled components shall be placed steadily. During the repair of tire assembly or replacement of inner tube, the internal pressure inside the tire shall be released first and protection frame shall be prepared. 1

Chapter I Safety precautions 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20.

Protection frame or protection net shall be used when retainer is being disassembled to prevent injury due to release of retainer elasticity. Protection frame shall be used during tire inflation to prevent the ejection of retainer and retainer ring or tire burst, etc. due to excess air pressure. After tire inflation, barometer shall be used to check the tire pressure and excess pressure shall be released. When operation is conducted under lift arm, the lift arm shall be placed on the protection bracket or installed with special cylinder protection bracket; When pneumatic or electric tools are used, operation shall be conducted strictly according to stipulations. When engine and gearbox-torque converter assembly are being disassembled, the core components of converter may drop and cause injury, so protection measures shall be adopted. When transmission shaft is disassembled, the spline shaft in the middle may disengage and cause injury, so protection measures shall be adopted. When components with residual oil are gripped by hand, they may slip and cause injury, so protection measures shall be adopted. When oil is sprinkled on the ground, people may slip and get injured, so protection measures shall be adopted. When welding is conducted directly on the machine, proper grounding near the welding point shall be ensured, otherwise the electric line throughout the machine, tire or other non-metal components may be burnt or fire hazard may occur. High-pressure fluid leakage, even leakage as small as a pinhole, may penetrate human tissue and cause serious injury or even death. If fluid permeates skin, the injury must be treated immediately by a doctor who is familiar with such kind of injury. During check of leakage, a wood board or thick board shall be used as shield.

III. Safety precautions for commissioning 1. 2. 3. 4. 5. 6. 7. 8.

Prior to the start of the complete-loader, the gear shall be at the neutral position, the hand brake shall be released, various oil, lubrication grease, water or antifreeze fluid shall be filled, irrelevant personnel are not allowed to be around the machine, and horn shall be blown for warning; Various control cable shall be commissioned to be accurate and reliable, and the service brake and parking brake system shall be the first priority to be commissioned; The over-pressure protection switch of air reservior shall be checked to operate properly; Various instrument display and back-up alarm devices shall be checked to operate properly; The turn light and work light shall be checked to operate properly; The back-up mirror shall be adjusted to the right angle; The original safety signs on the loader shall be checked; any missing sign shall be supplemented; The loader shall be kept at idle speed before running till the braking pressure reaches standard.

2

Chapter 2 Picture and parameters of complete-loader

Chapter 2 Picture and parameters of complete-loader

Overall Dimensions Code

Figure 2-1 Description

Dimension

A

Overall length

7390 mm

B

Wheel base

2850 mm

C

Minimum ground clearance

347 mm

D

Maximum total height of main unit

3180 mm

E

Pin height at maximum lifting

3710 mm

F

Dumping height

2890 mm

G H I

Distance between bucket tooth and ground at dumping Dumping reach Distance between rear shaft and hinge joint

2747 mm 1083 mm 1425 mm

J

Length of rear suspension

2045 mm

K

Height of delivery location

400 mm

L

Overall height at maximum lift

4720 mm

a2

Dumping angle

450

3

Chapter 2 Picture and parameters of complete-loader

Standard specifications

Item

Specs

Bucket capacity

1.7 m3

Rated load

3500kg

Lift arm lifting time

≤5.5s

Total time

≤10.5s Forward gear I

6.5km/h

Reverse gear I

6.8km/h

Maximum speeds at

Forward gear II

12.0km/h

various gears

Reverse gear II

12.5km/h

Forward gear III

32.0km/h

Reverse gear III

33.5km/h

Traction force

106±3kN

Maximum breakout force (rotating bucket)

103±3kN

Maximum grade ability

28 ゜

Performance Minimum turning

Tire center

6240 mm

radius

Outside of bucket

5445 mm

Length of loader (while the bucket is put on the ground horizontally)

Geometric dimension

Weight of loader

7390±100mm

Width of loader (outside of wheel)

2320±50mm

Bucket width

2600±30mm

Height of loader (top of the cab)

3180±30mm

Wheel base

2850±30mm

Wheel tread

1850±10mm

Minimum ground clearance (at the hinge joint)

347±20mm

Dumping height

2890±50mm

Dumping distance at maximum lifting

1083±50mm

11620±300kg

4

Chapter 2 Picture and parameters of complete-loader

Item Engine

Specification

Type

Weichai WP6G140E22

Rated rotating speed

2200r/min

Maximum torque

560N·m /1400-1600r/min

Rated fuel consumption

≤225g/kW·h

Consumption rate (bench test) Fuel oil (customers may choose the type of fuel oil

Light diesel oil No.0

according to the local ambient temperature) Diameter of fan (backward air exhaust)

Φ600mm

Hydraulic

Single-stage three-elements (single

Type

torque converter Transmission

Gearbox

system

turbine) Torque coefficient

3.45±5%

Cooling method

Water-cooling pressure circulating

Type

Fixed shaft power gear shift

Shifts of gearbox

Three forward gears Three reverse gears

Main drive and

Transmission oil pump

Gear pump

Working pressure

1.1~1.5MPa

Main drive type

Helical bevel gear

hub reduction

One-stage reduction Wheel hub reducer type

Straight-toothed cylinder gear Planetary gear reducer

Reduction ratio

20.521

Main drive reduction ratio

5.286

Hub reduction ratio

3.882

Drive axle and

Type

One-stage bevel gear reduction

wheel

Tire

17.5-25

Air pressure of tire

Front wheel 0.32±0.01MPa

tire E-3/L-3PR

Rear wheel 0.28±0.01MPa Braking

Drive

Braking type

Single-line dry type brake

system

Braking

Diameter of brake disc

450mm

Diameter of brake cylinder

Φ75mm (8pcs X 2)

Effective area of friction plate

176.3 mm2 (4pcs X2)

Parking &

Braking type

Soft shaft control clamp plate type brake

emergency

Opening

braking

caliper

pressure

of

brake

04Mpa

5

Chapter 2 Picture and parameters of complete-loader

Steering system

Item Type Number of steering diameter × travel Steering pump

Working hydraulic system

Electric system

Name of oil (Oil filling)

Specification

cylinders

–

inside

CBAK3112 (shared with working system)

System working pressure

14MPa

Steering angle

35° to the left or right

Number of lift arm cylinders -- inside diameter × travel Number of rotating bucket cylinders -- inside diameter × travel Distribution valve

2-φ125×784mm

Type

DF32.2C

Working pump displacement

112ml/r

Flow/rotating speed

246L/2200r/min

system working pressure

16MPa

Control type

Hydraulic pilot control

System voltage

24V

Capacity of storage battery

2-N105

Voltage of bulb

24V

Start of diesel engine

24V electric start

Fuel oil tank: total volume is 200L

Customers shall fill the oil to the upper oil mark of 140L (the actual oil filling volume is subject to the scale of oil level gauge) Customers shall fill the oil to the upper oil mark of 140L (the actual oil filling volume is subject to the scale of oil level gauge) 17L (the actual oil filling volume is subject to the scale of oil level gauge) 36L (the actual oil filling volume is subject to the scale of oil level gauge) 18.5L (the actual oil filling volume is subject to the scale of oil level gauge) 18.5L (the actual oil filling volume is subject to the scale of oil level gauge) 6L Diesel engine coolant 5000 (an error within 10%) R134a 3500 (an error within 10%) 24V

Hydraulic oil tank: the total volume is 200L Crank case: engine oil Gearbox system: hydraulic transmission oil Axle (main drive reducer and hub reducer) Air conditioning system

Hinged frame, Fully hydraulic steering system 2-φ80×315mm

Front axle gear oil Rear axle gear oil

Front and rear booster pumps Warm air Working medium Heating capacity (W) Cool air Working medium (W) System voltage

1-φ140×553mm Hydraulic pilot double valve

6

Chapter 3 Maintenance point of complete-loader

Chapter 3 Maintenance points of complete-loader

I.

Diagram of lubrication points

Points of grease injection are at various sliding bearings or rolling bearings, including: 1. Bearing at the joint spider of transmission shaft. 2. Pin bushes at both sides of all oil cylinders. 3. Pin bushes that connect front and rear car frames; swing pin pushes of subframe 4. Various pin bushes of operating devices. Grease shall be injected to the aforesaid positions according to the requirements in the diagram. The injection shall be conducted in time according to operating conditions.

II. Maintenance cycle table Instruction for using maintenance cycle table: Before any operation or maintenance, instructions for complete-loader safety information, warning information and descriptions in the instruction manual and this Manual shall be read carefully and fully understood. Users are responsible for maintaining the loader. The maintenance includes adjustment during use, adding of lubricant during use, supplement of operating fluid of complete-loader, replacement of filter, and replacement of accessories caused by normal wearing and aging. In case maintenance is not conducted according to correct interval and steps, performance of product may be reduced and wearing of components may be accelerated. Notes: 1. Before every new maintenance cycle, all the previous maintenance cycles must be completed; 2. A maintenance cycle shall be determined according to working time. If a maintenance plan is carried out more conveniently according to calendar time, and the numerical readings are close to the working time, then the calendar time cycle (every day, every year, etc.) may replace the working time cycle. No matter the maintenance is calculated according to working time or calendar time, the closer maintenance cycle will have priority, and the maintenance shall be conducted according to the closer cycle; 3. Under extreme, dusty and humid working conditions, the specified time in the maintenance cycle table must be shortened, and the complete-machine maintenance must be conducted more frequently; 4. During maintenance, the maintenance items of shorter cycles shall be conducted simultaneously. For example, while the maintenance for every 500 working hours or every three months is conducted, the maintenance items for every 250 working hours or every month, for every 100 working hours or every half month, and for every 10 working hours or every day shall be conducted simultaneously, 7

Chapter 3 Maintenance point of complete-loader

I. Daily maintenance items for every 10 hours or every day 1. The coolant of engine shall be checked to ensure that it has been filled up; 2. The engine oil level of the engine shall be checked to ensure that the height of oil is within the normal working scope 3. The fixing bolts and nuts of the engine, gear box, drive axle and wheel rim shall be checked to ensure that they are not loose; 4. The air pressure of front and rear tires shall be checked to ensure that the pressure is normal; at the same time, the tires shall be ensured to have no abnormal wearing; 5. As for an air-pressure braking loader, all the air reservoirs shall be tested with water discharge operation; as for a hydraulic braking loader, such test is not necessary; 6. The oil level of hydraulic oil tank and gear box shall be checked; 7. Water shall be discharged from the coarse strainer (oil water separator) of the fuel oil system of the engine; 8. According to the requirements of Lubrication Points Indication, grease shall be injected into various hinge joints and shaft sleeves. 9. The oil, water and gas in various systems shall be checked to ensure that there is no leakage; engine fan and drive belt shall be visually inspected to ensure that they are not loose or damaged; the bucket teeth and main cutting-board of the bucket shall be checked and replaced if necessary. 10. The following components shall be checked to ensure that they operate properly: instruments of complete-loader, working lamps of complete-loader, safety belt of chair, reverse warning system, braking system of complete-loader, and steering system of complete-loader; 11. The starting performance, color of exhaust, and operating sound shall be checked to ensure that they are normal; 12. Various switches, fast connectors, control rods, pedals, joysticks, buttons shall be ensured to work properly; 13. The operation of the complete-machine shall be closely observed for 10 minutes to see whether there is abnormal sound or alarm due to local overheating, etc.

II. Maintenance items for every 50 hours or every week 1. The fixing bolt and nets of all the transmission shafts shall be fastened to ensure there are no loose bolts and nuts. 2. The braking fluid of the complete-load shall be checked and supplemented; (note: the supplemented braking fluid must be the same type as the original fluid, otherwise the original fluid must be completely discharged at the position of the wheel braking clamp before new braking fluid is added) 3. The gap between the brake shoe and the brake disc of the parking brake shall be checked and adjusted in case the gap is not appropriate. 4. After one or two operating cycle of the complete-loader, the oil level of hydraulic oil tank and gearbox shall be checked after the engine is shut down; The oil shall be supplemented if necessary (note: the supplemented oil shall be same type as the original oil, otherwise the service life the oil will be affected.) 5. If it is the maintenance of the complete-loader after the first 50-hour operation, the following operation shall be conducted, otherwise the following shall be neglected; the engine oil and engine oil filter shall be replaced. 6. The oil level of the wheel gears at both sides of the drive axle and the oil level of the main drive gear at the middle of the axle housing shall be checked; the oil shall be supplemented if necessary; (note: the supplemented oil shall be the same type as the original oil, otherwise the service life of oil will be affected.)

8

Chapter 3 Maintenance point of complete-loader

III. Maintenance items for every 100 hours or every half month 1. All the sundries on the wind radiator shall be cleaned to ensure that the radiator system of the complete-loader is able to radiate heat properly; 2. The oil filling filter screen and clean breather of the air filter on the fuel oil tank and hydraulic oil tank shall be cleaned; 3. If it is the maintenance of the complete-loader after the first 100-hour operation, the following operation shall be conducted, otherwise the following shall be neglected: (1) The transmission oil of gearbox, and the oil filter and oil strainer of the gearbox-torque converter assembly (the filter is an optional component, not every loader has such component) shall be replaced; the gearbox sump shall be opened and reinstalled after the filter screen and magnet have been conscientiously cleaned.

IV. Maintenance items for every 250 hours or every month 1. The air intake system of the engine shall be checked. The service indicator of air filter shall be visually inspected. If the yellow piston of the indicator rises to the red area, the filter element of the air filter shall be cleaned or replaced. 2. The tightening torque of the fixing bolts of the wheel rims shall be checked. 3. The stressed weld joints and fixing bolts of the working devices and front and rear frames shall be checked to ensure that there are no cracks and looseness. 4. The tension and damage of drive pulley of engine, belt of compressor of air conditioner, belt of generator shall be checked; 5. The gap between the brake shoe and the brake disc of the parking brake shall be checked and adjusted in case the gap is not appropriate; 6. All the fixing bolts of the storage battery shall be tightened and the top of storage battery shall be cleaned. 7. The engine oil and the engine oil filter shall be replaced; and water shall be removed from the oil-water separator connected to the engine (the filter is an optional component, not every loader has such component); 8. If it is the maintenance of the complete-loader after the first 250-hour operation, the following operation shall be conducted, otherwise the following shall be neglected: operating hydraulic oil shall be collected and filtered, oil suction filter element of hydraulic oil tank shall be replaced, return oil filter element shall be replaced, the interior of hydraulic oil tank shall be cleaned, the filtered hydraulic oil shall be refilled into the hydraulic oil tank and the oil shall be supplemented and kept at an appropriate level. (Note: when the filter element of hydraulic oil is replaced, the original hydraulic oil must be filtered or replaced)

V. Maintenance items for every 500 hours or every three months 1. The bolts that connect the front and rear axles and the frame shall be fastened; 2. The engine oil, the engine oil filter, the fuel oil filter and the filter element of the oil-water separator shall be replaced (the filter is an optional component, not every loader has such component); 3. The hinge bearing plate bolts of the front and rear frames shall be checked to ensure that they are not loose. 4. The brake pads and brake discs shall be checked, and the thinner-than-14mm brake pads and damaged brake discs shall be replaced. 5. The operating hydraulic oil shall be collected and filtered, the oil suction filter element of hydraulic oil tank shall be replaced, the hydraulic oil tank shall be cleaned, the filtered hydraulic oil shall be refilled into the hydraulic oil tank and the oil shall be supplemented and kept at an appropriate level. (Note: when the filter element of hydraulic oil is replaced, the original hydraulic oil must be filtered or replaced) 9

Chapter 3 Maintenance point of complete-loader 6. The transmission oil of gearbox, and the return oil filter of the gearbox-torque converter assembly shall be replaced. The gearbox sump shall be opened and reinstalled after the filter screen and magnet have been conscientiously cleaned. 7. The oil level of the wheel gears at both sides of the drive axle and the oil level of the main drive gear at the middle of the axle housing shall be checked; if the operating time has not exceeded 500 hours, the gear oil of the drive axle shall be replaced at least once a year.

VI. Maintenance items for every 1000 hours or every half year 1. Hydraulic oil, return oil filter element and oil suction filter element shall be replaced, and the hydraulic oil tank shall be cleaned. 2. The brake system shall be checked, the booster pump shall be cleaned and brake oil shall be replaced; 3. The diesel oil tank and diesel oil filter shall be cleaned; 4. The diesel oil filter of the engine shall be replaced; 5. The roll over protection structure shall be checked; (equipped with an roll over protection bracket) 6. The dryer of the braking system shall be replaced. (This is an optional component and shall be replaced according to loader models) Note: As a part of the maintenance plan, the maintenance of diesel engine (e.g. replacement of engine oil, maintenance of air filter, etc.) shall be conducted in compliance with the attached document: Instruction for Usage and Maintenance of Diesel Engine. In case there are discrepancies between the aforesaid and the Instruction, the attached Instruction for Usage and Maintenance of Diesel Engine shall prevail. The following Registration Form of Stage Examination and Maintenance of Loader shall be filled in by local agents after the sales of a complete-loader is completed; if the product malfunctions later, the Form shall be provided while the customer claims compensation from Lonking.

10

Chapter 3 Maintenance point of complete-loader

Registration Form of Stage Examination and Maintenance of Loader Maintenance item

50h

100h

250h

500h

Operating time 50h

●

100h

●

150h

●

200h

●

250h

●

300h

●

350h

●

400h

●

450h

●

500h

●

550h

●

600 h

●

650h

●

700h

●

750h

●

800h

●

850h

●

900h

●

950h

●

1000h

●

1050h

●

1100h

●

1150h

●

1200h

●

1250h

●

1300h

●

1350h

●

1400h

●

1450h

●

1500h

●

1550h

●

1000h

Date of examination

Examiner

Brief description of defect

● ● ● ● ● ●

●

●

● ● ● ● ● ●

●

●

●

● ● ● ● ● ●

●

●

11

Chapter 4 Standard Data Sheet

Chapter 4 Standard Data Sheet

1. Standard tightening torque of bolts and nuts (1) Standard tightening torque a. Table of tightening torque of ordinary bolts Strength grade of bolt

Nominal diameter of bolt (mm)

Nominal diameter of bolt (mm) 6 8 10 12 Tightening torque (N.m)

14

16

18

20

4.6 5.6 6.8 8.8 10.9 12.9

240 300 480 640 900 1080

4~5 5~7 7~9 9~12 13~16 16~21

55~70 70~90 93~124 124~165 180~210 209~278

90~110 110~140 145~193 193~257 280~330 326~434

120~150 150~190 199~264 264~354 380~450 448~597

170~210 210~270 282~376 376~502 540~650 635~847

Strengt h grade of bolt 4.6 5.6

Nominal diamete r of bolt (mm) 240 300

6.8

10~12 12~15 17~23 22~30 30~36 38~51

20~25 25~32 33~45 45~59 65~78 75~100

36~45 45~55 58~78 78~104 110~130 131~175

Nominal diameter of bolt (mm) 22 24 27 Tightening torque (N.m)

30

33

36

39

900~1100 1120~140 0 1694~225 9 2259~301 2 2800~335 0 3812~508 4

928~1273 1160~154 6 1559~207 9 2932~389 8 4111~548 1 4933~657 7

230~290 290~350

300~377 370~450

450~530 550~700

540~680 680~850

670~880 825~1100

480

384~512

488~650

714~952

969~1932

8.8

640

512~683

651~868

952~1269

10.9

900

740~880

940~1120

12.9

1080

864~115 2

1089~146 4

1400~165 0 1606~214 2

1293~172 3 1700~200 0 2181~290 8

1319~175 9 1759~234 5 2743~329 8 2968~395 8

b. Table of tightening torque of ordinary rubber pipe (specification of open-end spanner and Table of Recommended Thread Torque) Thread M12X1.5 M14X1.5 M16X1.5 M18X1.5 M20X1.5 M22X1.5 M24X1.5 M26X1.5 M27X1.5 M30X2 M36X2 M42X2 M45X2 M52X2

1. Metric Thread

N.M NUT TORQUE 10-20 20-35 25-40 30-45 35-50 40-70 40-70 60-100 80-120 100-150 150-220 180-250 200-300

Specification of spanner opening mm 17 19 22 22 or 24 27 27 32 32 36 41 50 55 60

12

Chapter 4 Standard Data Sheet

2. Thread adhesive No. Name specification series) 1 AT598 2

AT515

3

AT577

4

AT262

5

AT243

and (Aotai

Dosage for 100 units

Usage

Remark

2 canisters (300ml) 5 canisters (300ml) 5 barrels (300ml) 3 bottles (250ml)

Thread sealing for drive axle plug,

Or Debang 2577 Or Debang 2515 Or Debang 2577 Or Debang 2243 Or Debang 2243

8 bottles (250ml)

Plane sealing for articulated interface between diesel and torque converter Thread sealing for joint of fan heater, joint of unloading valve and air reservoir joint Thread sealing for pin bolt of oscillating axle Thread sealing for steering shaft. Thread sealing for oil drain plug of hydraulic oil tank and fuel oil tank.

3. Code of electric wire Function

Electric circuit

Battery charging

Start

Grounding Flameout Fan heater Power supply of main circuit

Wiper

Code

Color

Diameter of wire

1 1C 3 3a 1a 4 2c 0 0A 0B

Red Red Grey Grey Red Brown White Black Black Black

1.5-5.0 6.0 1.5 1.0 1.5 1.5 1.5 1.1-4.0 1.5 2.5

42 42a 27 58 2 2a 2b 33 59 62 75 78 79

White Yellow Red Yellow Purple Red Red Red Green Yellow Red Purple Purple

2.5 1.5-2.5 1.0-1.5 2.5 1.5-2.5 2.5 2.5-5.0 1.0 1.0 1.0 1.0 0.85 0.85

13

Chapter 4 Standard Data Sheet

Function

Electric circuit

Load power supply

Illumination

Instrument Warning

Function

Signal

Others

Electric circuit

Code

Color

Diameter of wire

6 7 11 16 24 32 40 66 69 83 97 8 9 14 15 29 56 34 51 53 75

Orange Brown Orange Pink Green Purple Brown Yellow Blue Grey Blue Pink White Orange Red Brown Purple Pink Purple Brown Red

1.0-2.5 2.5 2.5 1.5 1.0 1.5 1.5 1.5 1.5 1.5 2.5 1.5 1.5 1.5 1.5 1.5 1.5 1.0 1.0 1.0 1.0

Code

Color

Diameter of wire

12 17 22 23 93 25 26 61 19 21 35 40

White Purple Green Blue Yellow Grey Red Red Brown Purple Green Brown

1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.5 1.0 1.5

14

Chapter 4 Standard Data Sheet

4. The grade, specified volume and additive volume (adopt international label and measurement unit) of engine oil, gearbox oil, hydraulic oil, drive axle oil, hinge pin grease, diesel oil and antifreeze recommended for various temperature ranges between -30 to +50℃. Type of oil

Engine oil

Ambient temperature

API CF-4 and above

Capacity Filling quantity

17L 36L

Hydraulic transmission oil

173L Hydraulic oil

18.5L Drive axle gear oil Lubrication grease Diesel oil

25L Anti-freezing fluid

15

Chapter 4 Standard Data Sheet

5. Conversion table Conversion from millimeter to inch · ···················· 1mm=0.03973 inch

Conversion from kilogram to pound ·····················1kg=2.2046Ib

16

Chapter 4 Standard Data Sheet

5. Conversion table

Conversion from kilogram to US gallon ·····················1liter = 0.2642 US gallon

Conversion from liter to UK gallon ·····················1liter = 0.21997 UK gallon

17

Chapter 4 Standard Data Sheet

5. Conversion table Conversion from kilogram·meter to foot·pound ·····················1kgm=7.232ft·Ib

18

Chapter 4 Standard Data Sheet

5.

Conversion table

Conversion from kilogram/centimeter2 to pound/inch2 •••••••••••••••••••••1kg/cm2=14.2233Ib/in2

Temperature Conversion between Fahrenheit and Celsius A simple way to convert Fahrenheit readings to Celsius readings (or vise versa) is to refer to the numbers in the middle or boldface column of the attached table. These numbers represent Fahrenheit or Celsius readings If you want to convert Fahrenheit readings to Celsius readings, you shall consider the middle column as the column of Fahrenheit readings, and the column at the left side of the middle column is the column of Celsius readings If you want to convert Celsius readings to Fahrenheit readings, you shall consider the middle column as the column of Celsius readings, and the column at the right side of the middle column is the column of Fahrenheit readings

19

Chapter 4 Standard Data Sheet

Table of conversion between Celsius and Fahrenheit ················ 1℃=33.8℉

20

Chapter 5 Troubleshooting Table of Contents

Chapter 5 Troubleshooting Table of Contents

5-1 Torque converter and gearbox system.........................................................................................[22] 5-2 Drive axle system.............................................................................................................................[39] 5-3 Working hydraulic system...............................................................................................................[42] 5-4

Pilot control system................................................................................................................................... [48]

5-5 Steering hydraulic system.............................................................................................................. [54] 5-6 Foot brake system........................................................................................................................... [58] 5-7 Electric system................................................................................................................................. [61]

21

Chapter 5 Troubleshooting Table of Contents

22

Chapter 5 Troubleshooting Torque Converter and Gearbox System

Precautions for the installation, maintenance and repair of torque converter and gearbox are as follows: 1. Pressure control: The oil inlet pressure of torque converter shall be controlled at 0.45-0.65MPa. The outlet pressure of torque converter shall be controlled at 0.25-0.35MPa. The pressure of lubrication oil shall be 0.1-0.2MPa, The speed-changing working pressure shall be1.5-1.7MPa.

5-1.Malfunction cases of torque converter and gearbox:

5-1-01. Excessively rapid rise of oil temperature of gearbox and water temperature of engine .....[23] 5-1-02. When the loader is shifted to gear I or III, the loader cannot run until a few minutes later.r[25] 5-1-03. After Gear II is shifted, the loader will not run until several minutes later .............................[26] 5-1-04. After gear shift, the pressure cannot reach the normal value .................................................[27] 5-1-05. Insufficient pressure of various gears, and insufficient driving and operating power ..........[28] 5-1-06. When the loader is under normal operation，the oil temperature of the gearbox will exceed 120℃ in short time ......................................................................................................................................[29] 5-1-07. A loader does not run at cold start, but after the engine is heated for a while, the loader starts to run (after the loader is started and the gear is shifted, the loader does not run. However, after the engine is heated for a while, the loader starts to run)..............................................................................[29] 5-1-08. The loader runs at cold start, but when the engine temperature rises, the loader stops running (runs for a while and stops for a while)........................................................................................ [30] 5-1-09. During the operation, the loader may suddenly stop, which is similar to automatic emergent braking ........................................................................................................................................................... [31] 5-1-10. The pressure is normal at any gear, but the loader cannot run ..............................................[33] 5-1-11. No matter which gear is shifted, there is no pressure and the loader cannot run. Meanwhile, the steering and lifting of lift arm do not work ..........................................................................................[33] 5-1-12. The oil level of the gearbox rises rapidly ....................................................................................[34] 5-1-13. The oil level of the gearbox declines rapidly ..............................................................................[35] 5-1-14. The pressure of various gears is normal, but the cut of the bucket is powerless and there is a “drumming” sound form the gearbox ........................................................................................................ [35] 5-1-15. the pressure of gear I is not sufficient

[35]

5-1-16. Gearbox releases abnormal sound .............................................................................................[36] 5-1-17. Common Malfunctions and Troubleshooting Methods of Troque Converter ........................[38]

23

Chapter 5 Troubleshooting Torque Converter and Gearbox System

Malfunction case 5-1-01: Excessively rapid rise of oil temperature of gearbox and water temperature of engine Description of malfunction Under the normal operation of loader, the oil temperature of gearbox rises above 120℃ in very short time. The water temperature of engine rises above 95℃. After the engine is shut down and cooled down, it may continue to operate again. Possible reasons: This is a rare phenomenon. Generally speaking, the main factors include: working condition, usage method, altitude, heat dissipation effect, malfunction of the loader itself, etc. The engine: 1. Special working condition 2. Improper usage 3. Damage of instruments and electric devices 4. Coolant is not enough and the return water pipe is blocked. 5. Thermostat is damaged or the working efficiency of water pump decreases. 6. The throttle control cable or flameout cable of the engine get stuck and are not in the right position. 7. The fan belt is too loose, the water tank is too dirty or the installation distance of the wind scooper does not comply with requirements. 8. The air filter element is too dirty. 9. The dissipation effect of the engine oil radiator is not good or the cylinder cover leaks gas or water. 10. The pressure of oil injector is adjusted too high. Gearbox-torque converter assembly 1. Damage of sensor and instrument. 2. Improper oil use or deterioration of oil or blocking of filter screen. 3. The dissipation effect of cooler of gearbox-torque converter assembly is not good or the pressure of return oil is too high. 4. The oil suction pipe of variable speed pump is flat or the variable speed pump leaks internally. Inspection steps or actions Precondition 1: the working condition shall be confirmed. Special working environment such as paper mill. Precondition 2. The operating method shall be confirmed. The loader shall not be operated under heavy load for a long time or climb long slope continuously and the slope gradient shall not be higher than 30 degree. During operation, the loader shall be operated at gear I, and the throttle control shall be adjusted reasonably according to the work load. Precondition 3. The area where the heat comes from shall be identified, is it the engine or the gearbox?, if the heat of engine makes the temperature of gearbox higher, the steps for checking high water temperature of engine shall be followed; if the heat of gearbox makes the temperature of engine higher, the steps for checking high oil temperature of gearbox shall be followed. 24

Chapter 5 Troubleshooting Torque Converter and Gearbox System

Steps for checking high water temperature of the engine: 1. The water temperature sensor and instrument shall be checked to see if they are damaged. 2. The coolant shall be checked to see if it is sufficient, and the return water pipe of the water tank shall be checked to see if it is blocked. The water tank cover shall be checked to see if it is damaged. For ordinary regions, the opening pressure of water tank cover shall be set at 0.05MPa; for plateau regions, the pressure shall be set at 0.07MPa. 3. The thermostat of the engine shall be checked to see if it has been turned on. 4. The water pump shall be checked to see if it works properly. At the same time, the water suction pipe of the pump shall be checked to see if its inner layer falls off or it becomes flat or the caliber becomes smaller. 5. The throttle control cable or flameout cable of the engine shall be checked to see if they are stuck 6. The tightness of fan belt shall be checked and the water tank shall be cleaned. 7. The distance between the fan and the wind scooper shall be checked. 8. The air filter element shall be checked. 9. The engine cooler shall be checked to see if it is blocked. 10. The cylinder cover shall be checked to see if there is leakage of water or gas. 11. The opening pressure of oil injector shall be checked to see if the pressure is too high.

Steps for checking the gearbox 1. The oil temperature meter and oil temperature sensor shall be checked to see if they are accurate. 2. The oil (filling amount and oil quality) used by the torque converter shall be checked to see if the oil complies with the requirements. 3. The oil bottom filter screen and oil filter of the gearbox shall be checked. (See Figure 5-01)

Filter screen

Figure 5-01 25

Chapter 5 Troubleshooting Torque Converter and Gearbox System

4. The gearbox oil radiator shall be checked. 5. The return oil pressure of torque converter shall be checked to see if the pressure is too high, which may cause the fluidic resistor of the return oil system to be high and the oil temperature to rise rapidly. 6. The oil suction pipe of the variable speed pump shall be checked to see if the pipe is sucked flat or blocked. 7. The internal leakage volume of the variable speed pump shall be checked to see if it is within the normal scope. 8. The speed changer - torque converter assembly shall be checked to see if there is internal malfunction.

Malfunction case 5-1-02: When the loader is shifted to gear I or III, the loader cannot run until a few minutes later. Description of malfunction. After gear shift, the pressure of gearbox rises slowly, the oil temperature rises rapidly, and the pressure goes down after the engine is heated. However, gear II operates properly. Possible reasons: 1. Different gears of the gearbox use the same oil. The proper operation of gear II indicates that the oil itself is not the main reason that causes the shift delay of gears I and III. 2. Gear I and gear III are used more frequently, so the main reason is the gear I’s clutch. 3. The speed-changing control valve leaks internally or valve core or spring gets stuck. 4. Bolts of end cover are loose or sealing members of the clutch of gear I are damaged. 5. Fixing locking plates of the separating frame is bent or deformed or the piston travel of gear I is too long. 6. There are cracks on the oil pipe of gear I or the gap of end cover is not adjusted properly. Inspection steps or actions: 1. The speed-changing control system shall be checked to see if the connection is appropriate. A bad connection may lead to inaccurate shifting or slight deviation of gear from the right position. 2. The oil consumption of the gearbox shall be checked to provide convenience to the diagnosis of malfunction. The additive amount and oil specification shall be checked to see if they comply with requirements. 3. The oil bottom filter screen and the oil filter of the gearbox shall be disassembled to see if they are blocked. Meanwhile, the oil and filter screen shall be closed observed to see if the oil has deteriorated. Deteriorated oil will become black and stinky. The oil shall be checked to see if it contains aluminum powder, copper powder or other impurities. Among them, copper powder can be easily observed under the light (copper powder inside the oil cannot be easily identified inside the workshop) Under the sunshine, copper powder inside the oil can be clearly identified. This step is conducive to the initially identification of the malfunction position inside the gearbox. 4. The speed-changing control valve shall be disassembled to see if the inclined holes on the pressure reducing valve rod is blocked. (See Figure 5-02)

26

Chapter 5 Troubleshooting Torque Converter and Gearbox System

Speed-changing control valve

Figure 5-02 Speed-changing control valve 5. After the clutch is removed, the bolts of the end cover shall be checked to see if they are loose. Then the gear II clutch shall be dismounted to check if the piston is able to return. If the return is not complete, it will lead to serious shift delay of gear I and gear III. 6. The middle cover of gearbox shall be disassembled to check if the O-shaped ring between the oil inlet of gear I cylinder and the gearbox housing is misplaced or damaged. The misplacement or damage of this O-ring will cause the leakage of the oil that enters the gear I cylinder, which will lead to the delay of gear I engagement. 7.The piston travel shall be checked. The travel shall be controlled between 3.63mm and 5.5mm. If the wearing of friction plate is serous, the piston travel will become longer, which will lead to longer piston engagement time, and then cause shift delay. The piston travel control is usually calculated via the thickness of friction plate. The requirements for the thickness of the friction plates are: the cumulative thickness of 6 driving discs and 6 driven discs shall be controlled between 25.5mm and 26.1mm, and the maximum thickness shall not exceed 26.3mm. 8. The bearings, bolts, etc. shall be checked to see if they are damaged or loose. 9. The oil channels on the gear I and gear III housings shall be carefully checked to see if there are cracks.

Malfunction case: 5-1-03 After Gear II is shifted, the loader will not run until several minutes later Description of malfunction: After every gear shift, the pressure of gearbox increases slowly. After the engine is heated, the pressure will go down to an extent, but gear I and gear III operate properly. Possible reasons: The oil is shared by various gears of clutches. The proper operation of gear I and gear III indicates that oil 27

Chapter 5 Troubleshooting Torque Converter and Gearbox System is not the main reason that causes the shift delay of gear II. 1. Idle speed of engine is too slow. 2. There is dislocation after the speed-changing control rod becomes loose. 3. There are many impurities in the oil. 4. Seals on the transmission end cover are damaged. 5. The sealing members on gear II clutch piston are damaged. 6. There are sand holes are on the piston body or the piston is broken. Check steps or disposal measures: 1. The engine shall be checked to see if the idle speed is too slow and if the driver’s operation is correct. 2. The speed-changing system shall be checked to see if there is improper connection, which may cause inaccurate shifting or incomplete positioning of gears. 3. The oil-way system shall be checked. The bottom filter screen and oil filer of the gearbox shall be disassembled to see if they are blocked. Meanwhile, the oil and filter screen shall be closed observed to see if there are abnormal impurities in the oil or oil bottom filter screen, such as seals, bolts, etc. 4. The speed-changing control valve shall be assembled to check if the gear II oil-way is blocked or the paper gasket is damaged. 5. The gearbox end cover shall be disassembled to check if the O-ring and oil seal of the end cover are damaged. 6. The gear II clutch shall be dismounted to check if the piston guide pin is broken, the wearing of friction disc and if the piston rings get stuck.

Malfunction case 5-1-04: After gear shift, the pressure cannot reach the normal value Malfunction description: After the loader is started, the pressure of various gears of the gearbox cannot reach the normal value (1.2MPa) Though the pressure of various gears is abnormal, the driving and operation are normal. Possible reasons: The pressure of various gears of the gearbox cannot reach normal value, but the driving and operation is normal. According to such characteristic, it can initially diagnosed that the torque converter and gearbox does not malfunction internally, but the malfunction exists between the speed-changing controller and the pressure meter, so the malfunction can be rapidly removed according to the following steps. Check steps and disposal measures: 1. The pressure meter shall be checked to see if it operates properly. If it is damaged, it shall be replaced by new meter. If the pressure meter is normal, please refer to the step 2. 2. The connecting pipes and joints of the pressure meter shall be checked to see if they are blocked. If they are blocked, diesel oil or gasoline can be used to clean the blocked position. 3. The pressure regulating spring of the speed-changing control value shall be checked to see if it is deformed (shortened, bent or broken)

28

Chapter 5 Troubleshooting Torque Converter and Gearbox System

Malfunction case 5-1-05: Insufficient pressure of various gears, and insufficient driving and operating power. Malfunction description: after the loader is started, the pressure of various gears of the gearbox cannot reach 1.2MPa. Meanwhile, the driving and operation are not normal. Possible reasons: According to the initial analysis of the malfunction, insufficient oil supply of the oil supply system causes insufficient pressure of various gears and the abnormal driving and operation. 1. Insufficient oil usage or improper oil usage. 2. The speed-changing control rod is loose or dislocated. 3. The pressure regulating spring of the speed-changing control valve is broken or the decompression lever is stuck. 4. The return of the stop valve rod of the speed-changing control valve is not in the right position. 5. The speed-changing control valve leaks internally. 6. The oil suction pipe of the variable-speed pump is blocked or the operating efficiency of the variable-speed pump declines. Inspection steps or actions: 1. The gearbox oil shall be checked to see if it is sufficient. If the oil is not sufficient, please add the hydraulic transmission oil of the same brand and same model. If the oil quantity is normal, please check the next step. 2. The speed-changing control rod shall be checked to see if it is dislocated. If it is dislocated, the oil inlets of various gears will not open completely, which will lead to insufficient gear pressure. After adjustment, the malfunction will be removed. If the speed-changing control rod is not dislocated, please check the next step. 3. The pressure regulating spring of the speed-change control valve shall be checked to see if it is broken. If it is broken, please replace the pressure regulating spring. If the pressure regulating spring is normal, please check the next step. 4. The pressure regulating valve rod of the speed-changing control valve shall be checked to see if they are stuck. If they are stuck and unable to return, diesel oil or gasoline can be used to clean them. If they are normal, please check the next step. 5. The stop valve rod of the speed-changing control valve shall be checked to see if it is stuck. If it is stuck, some pressure oil will directly flow back to the oil pool, which will cause insufficient pressure of various gears and insufficient driving and operating power. If the stop valve rod is not stuck, please check the next step. 6. The paper gasket at the main oil-way of the speed-changing control valve shall be checked to see if it is broken. When it is broken, the oil inside the speed-changing control valve will flow through the lubrication oil outlet back to the oil pool. Therefore, the malfunction will be removed if the paper gasket is replaced. If the paper gasket is normal, please check the next step. 7. The oil bottom filter screen shall be checked to see if it is blocked. If it is blocked, please replace the filter screen, filter element and gearbox oil. If the oil and filter screen is clean, please check the next step. 8. The oil sanction rubber pipe of the variable-speed pump shall be checked to see if the inner layer falls off or the pipe is blocked. When the inner layer falls off or the pipe is blocked, the oil suction will become difficult. The malfunction can be removed if the oil suction rubber pipe is replaced. If the rubber pipe is 29

Chapter 5 Troubleshooting Torque Converter and Gearbox System normal, please check the next step. 9. The speed-changing pump shall be checked to see if it leaks internally or it is burnt. If there is internal leakage or burn, the oil supply of the speed changer - torque converter assembly will be insufficient, and the speed-changing pump shall be replaced. If the oil supply of the speed-changing pump is normal, please check the next step. 10. The joint surface between the gearbox housing and the speed-changing control valve shall be checked to see if there are sand holes or cracks. If there are cracks, the large amount of pressure oil from the speed-changing pump will directly flow back to the oil pool, which will cause insufficient pressure of the system.

Malfunction case 5-1-06: When the loader is under normal operation ，the oil temperature of the gearbox will exceed 120℃ in short time. Description of malfunction: the oil temperature rises rapidly, but the pressure, driving and operation of the gearbox are normal, and the water temperature of the engine is also normal. Possible reasons: The reasons for causing the rise of oil temperature mainly include: influence of working condition, improper use such as long time overload operation, insufficient oil supply of the oil supply system, improper heat dissipation, etc. 1. Special working condition or application method (such as paper mill, upslope operation, etc.) 2. Damage of instruments or electric devices. 3. Improper use of oil. 4. The throttle or flameout cable of the engine is stuck. 5. The return oil pressure of the torque converter is too high. Inspection steps or actions: 1. The working condition and application methods shall be checked (long time heavy-load push operation or continuous upslope operation shall be avoided, and gradient shall not be higher than 30 degrees) The operation methods shall be checked to see if it is correct. During operation, the loader shall work at gear I and the throttle control shall match the work load. 2. The oil temperature sensor and the oil temperature meter shall be check to see if they are damaged. 3. The oil consumption of the speed changer - torque converter assembly shall be checked to see if it complies with the requirement. The filter element of the gearbox shall be replaced and the oil radiator of the gearbox shall be cleaned. 4. The throttle control cable or flameout cable of the engine shall be checked to see if they are stuck 5. The return oil pressure of the torque converter shall be checked to see if pressure is high, which will cause excessively high fluidic resistor and then lead to rapid rise of oil temperature.

Malfunction case 5-1-07: A loader does not run at cold start, but after the engine is heated for a while, the loader starts to run (after the loader is started and the gear is shifted, the loader does 30

Chapter 5 Troubleshooting Torque Converter and Gearbox System

not run. However, after the engine is heated for a while, the loader starts to run) Description of malfunction: After cold-start, no matter which gear is shifted, the loader does not run. However, when the oil temperature of the gearbox exceeds 50℃, the loader starts to run normally under any gear. Possible reasons: 1. The pipe joint is loose. 2. Improper use of oil. 3. The air does not circulate. 4. Oil inlet valve of torque converter is damaged or adjustment pressure is too high. 5. The stop valve of the speed-changing control valve does not return to the right position. 6. The speed-changing pump leaks internally. 7. The gap between the valve cartridge and the valve body of the speed-changing control valve is too wide, and the tightening torque of the fixing bolts of the control valve is not even. Inspection steps or actions: 1. All the pipe joints of the oil supply system of the gearbox shall be checked to see if they are loose. If pipe joints become loose, a great amount of air will enter the system (grease or soapy water may be used to conduct check) 2. The oil shall be checked to see if it is too thick. If the oil is too thick, the speed-changing pump will have difficulty in oil suction during cold start. 3. The air holes of the gearbox shall be checked to see if they are blocked. 4. Check, replace or adjust spring pressure. 5. The stop valve rod of the speed-changing control valve shall be checked to see if it is stuck. During winter, the freezing moisture brought by compressed air may occur at such position. 6. The speed-changing pump shall be assembled to check if the pump leaks internally. Meanwhile, the wearing of the spline of the speed-changing pump shall also be checked.

Malfunction case 5-1-08: The loader runs at cold start, but when the engine temperature rises, the loader stops running (runs for a while and stops for a while) Description of malfunction: After the loader is started, it is able to run normally at any gear. After the engine is heated, the running ability declines with the rise of the oil temperature, and the pressure of various gears goes down accordingly. In case of serious situations, the pressure goes down to zero and the loader stops running. However, after the engine is shut down for a while and restarted, the loader starts to run again, and such situation will go on repeatedly. What is noteworthy is that the pressure goes down as well at neutral position. Possible reasons: The malfunction symptoms and characteristics indicate that the running ability declines with the drop of pressure following the rise of oil temperature. There are a lot of reasons that may cause the rise of oil 31

Chapter 5 Troubleshooting Torque Converter and Gearbox System temperature, but the main reason for pressure drop lies in the oil supply system. In addition, when the oil supply system malfunctions, the oil temperature will inevitably rise. Therefore, the main reason still lies in the oil supply system. 1. Improper maintenance 2. The oil suction pipe of the speed-changing pump is sucked flat or blocked. Check step or disposal methods: 1. The cleanness of the oil of the speed-changing box shall be checked. If there are too many contaminants in the oil, the contaminants will concentrate at the oil outlet of the oil pan and block the oil outlet during oil suction, so the oil suction of the speed-changing pump is affected, and the pressure goes down and causes the declining of the running ability. However, after the loader is shut down for a while, the contaminants will scatter into the oil, the loader will be able to run again after starting, and such phenomenon will repeat. 2. The oil suction pipe of the speed-changing pump shall be checked. The inner layer of the oil suction rubber pipe of the speed-changing pump will become softer with the rise of the oil temperature, and then the oil suction rubber pipe may be blocked under the oil suction effect, so the oil suction of the speed-changing pump becomes difficult. When the peeling-off area is large, the oil suction pipe may be completely blocked, and the consequent insufficient oil supply may lead to low system pressure or even zero system pressure.

Malfunction case 5-1-09: During the operation, the loader may suddenly stop, which is similar to automatic emergent braking Description of malfunction: No matter the engine is hot or cold, the loader stops randomly and the gear positions are not clearly identifiable during shifting. However, the oil temperature and pressure are normal. Possible reasons: 1. The bolts of cab are loose or the speed-changing control rod is loose or dislocated. 2. The locating spring or locating slot of the speed-changing valve rod on the speed-changing control valve is damaged. Inspection steps or actions: 1. The fastening bolts of the cab shall be checked to see if they become loose. The loosened cab will move forward, backward, up and down under gravity and inertia, which will cause the speed-changing rod to move accordingly with cab, so the gears will not stabilize in the desired gears, but gear skipping or gear disorder will occur. (See Figure 5-04)

32

Chapter 5 Troubleshooting Torque Converter and Gearbox System

Figure 5-04 Position of the fastening bolts of the cab 2. Check the variable-speed joysticks. Adjust the control handle to the related joint level between variable speed control valves. (See Figure 5-05)

Figure 5-05 Diagram of the speed-changing control rod system 3. The speed-changing control valve shall be disassembled to check if the guide spring of the speed-changing valve rod is broken. Meanwhile, the guide ring groove of the speed-changing valve shall be checked to see if it is worn out.

33

Chapter 5 Troubleshooting Torque Converter and Gearbox System

Malfunction case 5-1-10: The pressure is normal at any gear, but the loader cannot run. Description of malfunction: though the loader cannot run, the oil temperature will rise rapidly and the steering and lifting of lift arm are normal. Possible reasons: 1. Inappropriate oil is used or maintenance is not conducted properly. 2. The valve rod of the speed-changing control valve is blocked. 3. The torque converter leaks internally or there are sand holes on wheel cover and pump impeller or the spring of the oil inlet overflow valve is broken. 4. The components of worm wheel are damaged. 5. The output shaft (fourth shaft) is twisted off. Inspection steps or actions: 1. The added volume of the gearbox oil and the oil specification shall be checked to see if they comply with the requirements (No.8 hydraulic transmission oil) 2. The speed-changing control valve shall be disassembled to see if the pressure-relief valve rod is blocked. After the pressure oil discharged by a blocked speed-changing pump meets the oil consumption requirements of the gearbox, a great amount of the remaining pressure oil cannot enter the torque converter, so the power is the torque converter is not sufficient. 3. The sump shall be disassembled to see if there is abnormal aluminum powder in the oil. Usually there is a great amount of aluminum powder in the oil after the torque converter is damaged. 4. The loader shall stop on a flat road surface. Meanwhile, the four tires shall be choked with hard objects. The access panel at the side of the torque converter shall be disassembled, and the speed-changing control rod shall be shifted the neutral position. Then the engine shall be started to see if oil is thrown away from the outer rim of the torque converter movement. If oil is thrown away, it indicates that the torque converter leaks seriously. If no oil is thrown away, the engine shall be shut down and other checks shall be conducted. 5.The oil return rubber pipe at the bottom of the torque converter shall be checked and then the engine shall be started to see if a great amount oil leaks while oil returns to the torque converter (while the torque converter operates properly, only a small amount of oil leaks from the torque converter) 6. The front output flange of the gearbox shall be disassembled to see if the fourth shaft is twist off. 7. The housing of the torque converter shall be disassembled to check if the valve core and spring of the overflow valve and back pressure valve are stuck or damaged. 8. The torque converter shall be disassembled to check the worm wheel components of the torque converter.

Malfunction case 5-1-11: No matter which gear is shifted, there is no pressure and the loader cannot run. Meanwhile, the steering and lifting of lift arm do not work. Description of malfunction: after the malfunction occurs, the engine operates properly, but the running of the complete-loader, steering and hydraulic system stop operating immediately. Possible reasons: 1. The spring plate, wheel cover or pump impeller breaks completely. Inspection steps or actions: 34

Chapter 5 Troubleshooting Torque Converter and Gearbox System This malfunction is typical, but the reason is specific. The torque converter shall be disassembled, the broken components (in most cases, the elastic bolts or wheel cover is broken) shall be replaced, and then the loader will operate properly.

Malfunction case 5-1-12: The oil level of the gearbox rises rapidly Malfunction description: cooling water enters the oil of the gearbox. Possible reasons: When the oil return pressure of the gearbox is adjusted to a relatively low level and the water pressure inside the water tank is relatively high, if the core pipe of the radiator is broken or has a loose weld, the cooling water will enter the oil the gearbox. Inspection steps or actions: The radiator shall be replaced. (See Figure 5-06)

Radiator

Figure 5-06 Radiator

35

Chapter 5 Troubleshooting Torque Converter and Gearbox System

Malfunction case 5-1-13: The oil level of the gearbox declines rapidly Malfunction description: hydraulic transmission oil enters the water tank. Possible reasons: When the oil return pressure of the gearbox is adjusted to a relatively high level, if the core pipe of the radiator is broken or has a loose weld, oil will enter the water tank. Inspection steps or actions; The radiator shall be replaced and the oil return pressure of the gearbox shall be re-adjusted (0.18-0.3MPa)

Malfunction case 5-1-14: The pressure of various gears is normal, but the cut of the bucket is powerless and there is a “drumming” sound form the gearbox. Malfunction characteristics: The pressure and response of various gears are normal (which indicates that there is no shift delay) Possible reasons: 1. The speed-changing control gears are not stable. 2. The components of the worm wheel are damaged. 3. The clutch slips. 4. The bearings are damaged. Inspection steps or actions: 1. The speed-changing control rod system shall be checked to see if it is accurate. 2. The sump shall be disassembled and the impurities in the oil shall be checked to determine the malfunction position. 3. If there is aluminum power in the oil, then the torque converter shall be disassembled to repair the components of the worm wheel. 4. If the oil turns black or there are small springs in the oil, then the gearbox shall be opened to check the second shaft and bearings.

Malfunction case 5-1-15: the pressure of gear I is not sufficient Description of malfunction: The pressure of gear II cannot reach the specified value (1.2-1.5MPa), but the pressure of gear I and gear III is normal. Possible reasons: 1. The position of gear II is not accurate. 2. End cover bolt is loose or sealing member on gear II cylinder is damaged. 3. Gear II cylinder or piston has cracks or other defects. 4. End cover gap is adjusted inappropriately. 36

Chapter 5 Troubleshooting Torque Converter and Gearbox System

Inspection steps or actions: 1. The gear positions of the speed-changing control rod system shall be checked to see if they are accurate. 2. The speed-changing control valve shall be disassembled to extensively check if the paper gasket of gear I of the control valve is broken or the oil-way of gear I is blocked. 3. The clutch of gear II of the gearbox shall be disassembled to check if the O-ring at the oil inlet of the cylinder body of gear II is damaged. If the ring is damaged, a great amount of pressure oil from the speed-changing control valve will leak from the damaged position to the oil pool, which will lead to insufficient pressure and shift delay of gear I. 4. The cylinder body and piston body of gear II shall be checked to see if they have cracks or sand holes. If there are cracks or sand holes, a great amount of pressure oil entering the cylinder body will leak out, which will cause insufficient pressure or even no pressure under serious situations. 5. When the fluororubber sealing members are taken out, the stuck phenomenon needs special attention. Then the fluororubber sealing members shall be checked to see if they are worn out or damaged. Meanwhile the thickness of the sealing members shall be checked to see it is even. If the thickness is not even, the position with thinner sealing members will be more likely to leak internally.

Malfunction 5-1-16: Gearbox releases abnormal sound Malfunction description: The noise is small during cold engine operation, but during hot engine operation, the noise becomes large. However, the pressure and operation of various gears are normal.

Possible reasons: 1. Too little or too much oil consumption 2. The oil suction pipe of the speed-changing pump is blocked or filter screen is blocked. 3. Bearings are damaged or the meshing clearance between gears is too large. 4. The elastic pins or retainer rings of torque converter fall off. 5. The meshing of gears is not regular. 6. Noise from the driving shaft of drive axle

Inspection steps or actions: The first test run: when the gear is at neutral position, the engine shall be started to check if there is abnormal noise at neutral position. If there is no abnormal noise at neutral position, it can be ensured that there is no speed-changing malfunction. Then the oil supply system and the torque converter shall be extensively checked. Check steps are as follows: 1. The oil bottom filter screen shall be disassembled to check the oil consumption situation, including 37

Chapter 5 Troubleshooting Torque Converter and Gearbox System added oil volume, oil specification and quality and oil cleanness. The oil shall be carefully checked to see if there are any impurities in the oil. Meanwhile, the tightness of the joints of the oil suction rubber pipe of the speed-changing pump and other pipes shall be checked and the oil shall be replaced. 2. After the oil is replaced, the second test run shall be started: if the abnormal noise at the neutral position still exists, the speed-changing pump shall be disassembled and the engine shall be started again (the engine running time shall be short) If the abnormal noise disappears, then the malfunction is caused by the speed-changing pump or a flat rubber pipe. If the abnormal noise still exists, then the malfunction is caused the torque converter. There are three reasons: 1. the bearings of the torque converter are damaged; 2. The friction between the pump impeller and the worm wheel or the fall-off of elastic pin; 3. The meshing between the transfer gear and the driving gear of the working pump or the driving gearing of the speed-changing pump is not regular. Among them, the check shall be focused on if the flat key between the pump driving gear and the driving shaft is worn out. The third test run: the front and rear driving shaft shall be disassembled, and then the test run shall be started at gear I, gear II and gear III. There are two kinds of test run results: 1. The abnormal noise disappears, so the noise comes from the driving shaft. The driving shaft shall be replaced. 2. The abnormal noise exists at gear I, gear II and gear III. Therefore, the gearbox shall be opened to check the speed-changing bearings.

38

Chapter 5 Troubleshooting Torque Converter and Gearbox System

Malfunction Case 5-1-17: Common Malfunctions and Troubleshooting Methods of Troque Converter Malfunction No. Low output torque

High oil temperature

S/ Cause N 1 Low output speed of engine 2 3 4 1 2 3

4 Clogged radiator and pipeline 5 Problem with cooling system 6 7

Low oil supply pressure

Low oil supply pressure of torque converter High oil temperature Use of unsuitable oil Insufficient oil charge Excessively high oil level Clogged oil filter

Loose connection of oil suction line High throttle, long-time slow operation

1 Insufficient oil 2

Insufficient oil supply or damage to variable speed pump

3 Excessively big internal leakage 4 5 Oil leak

High noise level

1 2 1 2 3

Damaged inlet valve or excessively low pressure setting Obstructed or unsealed oil suction line Damaged oil seal, paper gasket, O-ring Loosened thread connection Bearing failure Wear and tear of gear wheel and spline Broken retaining ring on turboshaft or guide impeller seat

Troubleshooting method Check and adjust the engine See the item on low oil supply pressure See the item on high oil temperature Replace it with the required oil Replenish it to the required value Drain the oil to an appropriate level Check and clean the oil filter Check and clean the radiator and check and fasten the pipeline Check the cooling system Adjust the operating cycle, reduce the operating load Damaged inlet valve or excessively low pressure setting Replenish it to the required value Check the wear and tear of oil pump Check the wear and tear of matching parts of seal ring, replace the seal ring Check, replace or adjust the spring Check the piping system Check, replace Check, fasten Check, replace Check, replace Check, replace

39

Chapter 5 Troubleshooting Drive Axle System

5-2.Malfunction cases of drive axle:

5-2-01.Insufficient driving force................................................................................................................... [39] 5-2-02.Wheel edges make a large noise during running ...................................................................... [39] 5-2-03.Main drive device makes an abnormal noise............................................................................... [39] 5-2-04.Loader makes abnormal noise during turning.............................................................................. [40]

Malfunction case 5-2-01: Insufficient driving force Malfunction characteristics: the pressure and response of various gears of the loader is normal. The loader may lose power suddenly during operation, but road running is normal. Possible reasons: The semi-axle of the front axle or the rear axle is twisted off, which causes the insufficient driving force. Check measures and disposal methods: 1. First the rear transmission shaft shall be disassembled, and then the engine shall be started and shifted to gear I. If the loader cannot run, then the semi-axle of front axle has already been twisted off. 2. If the loader can still run after the rear transmission axle is disassembled, then the rear transmission axle shall be installed and the front transmission axle shall be disassembled. If the loader cannot run, then the semi-axle of the real axle has already been twisted off. 3. As an alternative and direct way, the wheel edge covers of the front and rear axles can be disassembled to check if the semi-axles have been twisted off. Remark: if semi-axles are twisted off, the interior of the drive axles shall be cleaned before the semi-axles are replaced.

Malfunction case 5-2-02: Wheel edges make a large noise during running Malfunction characteristics: during running, the wheels swing noticeably left and right. Under serious circumstances, loader shakes or even is not able to run. Possible reasons: 1. The gap between wheel edge bearings is too large or the bearings are burnt. 2. Wheel edge gears are broken. 3. Round nuts at the wheel edge are loose. Inspection steps or actions: The wheel edge shall be dismounted for examination and repairing.

Malfunction case 5-2-03: Main drive device makes an abnormal noise Malfunction characteristics: the noise is more noticeable when the loader slows down during high speed straight line running. Possible reasons: 40

Chapter 5 Troubleshooting Drive Axle System Bearings are loose; The gap between driving gears and driven gears is too large or the meshing is not regular. Inspection steps or actions: 1. After the transmission shaft is disassembled, the input flange of the main drive device shall be held by both hands and pushed upward and pulled downward or pushed inward and pulled outward to see if it swings noticeably. At such time, if there is no obvious travel, we are able to confirm which main drive device (the front or the rear main drive device) malfunctions. 2. The main drive device shall be disassembled to check to the gap between the bearings of the driving spin chute gears and the gap between the supporting bearings of the left and right shell shaft journals. 3. The meshing surface and gap between the driving spin chute gears and driven spin chute gears. 4. The difference velocity device shall be disassembled to check the gap between bevel gears. Note: The installation shall be conducted strictly in compliance with the requirements for driving axle corresponding to various loader models.

Malfunction case: 5-2-04 Loader makes abnormal noise during turning Malfunction characteristics: the noise is more noticeable during turning, and the steering wheel feels heavy. Possible reason: the difference velocity device is damaged. Inspection steps or actions: The main drive device shall be dismounted to be repaired.

Forward stress surface

The contract surface is near the middle (slightly deviating to the flank at the larger end)

Larger end Backward stress surface

The contact surface is near the gear top of the larger end, but the stress is not concentrated on the gear top

Correct meshing of the driven spin chute gear Figure 5-06 The installation and adjustment methods of the main drive device are shown in the following table: Position of contact mark on driven gear face Drive forward

Drive back

Adjustment method Make driven gear move close to driving gear. If gear clearance thus becomes too small, move the driving gear outward.

Gear movement direction

41

Chapter 5 Troubleshooting Drive Axle System Make driven gear move away from driving gear. If gear clearance thus becomes too big, move the driving gear inward.

Make driving gear move close to driven gear. If gear clearance thus becomes too small, move the driven gear outward.

Make driving gear move away from driven gear. If gear clearance thus becomes too big, move the driven gear inward.

42

Chapter 5 Troubleshooting Working hydraulic system

5-3.Malfunction cases of working hydraulic system:

5-3-01.During the loading operation, suddenly the boom and the bucket are not able to work....... [42] 5-3-02.During loading, the bucket automatically turns upward.............................................................. [43] 5-3-03.During loading, the bucket is able to operate normally. However, after the bucket is taken back, it automatically turns downward........................................................................................................[44] 5-3-04.During loading, the bucket automatically turns upward when it hits a hard object, and after the bucket is taken back, it automatically turns downward............................................................................[44] 5-3-05.The bucket automatically turns downward when it is taken back, and the boom also automatically lowers after it is lifted............................................................................................................ [44] 5-3-06.he boom automatically lowers after it is lifted...............................................................................[45] 5-3-07.Lifting of bucket and boom is powerless....................................................................................... [46]

Malfunction case 5-3-01: During the loading operation, suddenly the boom and the bucket are not able to work Malfunction characteristics: When the malfunction occurs, the control rod, boom and bucket do not respond, but the steering is normal. Possible reasons: 1. The oil suction rubber pipe of the working pump is blocked. 2. The shaft of the working pump is twisted off. 3. The safety valve of the distribution valve is damaged. 4. The oil supply valve is damaged. 5. The pilot valve is damaged. Inspection steps or actions: 1. The suction pipe of the working pump shall be checked to see if the fall-off of inner layer causes the difficulty of oil suction. (See Figure 5-11)

43

Chapter 5 Troubleshooting Working hydraulic system

Working pump

Figure 5-11 Installation position of working pump 2. The oil outlet pipe of the working pump shall be disassembled, and the motor shall be clicked at idle speed (the engine shall not be completely started, otherwise oil liquidation will waste too much oil). At such time, if no oil emerges from the oil outlet of the working pump, then the shaft of working pump has already been twisted off or seriously worn out. 3. According to the second step test, if oil emerges from the oil outlet, a pressure meter shall be installed to measure the pressure of the system. Then the safety valve spring or O-ring of the distribution valve shall be checked to see if they are broken. 4. Pressure meter shall be installed to measure the oil outlet pressure of the oil supply valve. 5. Pressure meter shall be installed to measure the outlet pressure of the pilot valve. If the pressure of the oil supply valve is normal but the pressure of the pilot valve is abnormal, then the pilot valve is damaged.

Malfunction case 5-3-02: During loading, the bucket automatically turns upward Malfunction characteristics: when the bucket hits a hard object, it will automatically turn upward at a certain angle, but will not turn downward. Possible reasons: According to the malfunction characteristics, the bucket turns upward automatically but does not turn downward, which indicates that the cylinder sealing members of bucket are not damaged. If the cylinder sealing members of bucket are damaged, the bucket will turn upward and downward automatically, so the internal leakage of the cylinder can be eliminated at the first step. 1. The pressure of the small chamber overload valve is too low. 2. The sealing members of the small chamber overload valve are damaged. Inspection steps or actions: 1. A pressure meter shall be installed to measure if the small chamber overload pressure of the bucket cylinder is too low. Usually the small chamber overload pressure shall be set at 12MPa. 2. The small chamber overload valve shall be disassembled to check if the sealing members are damaged. 44

Chapter 5 Troubleshooting Working hydraulic system

Malfunction case 5-3-03: During loading, the bucket is able to operate normally. However, after the bucket is taken back, it automatically turns downward. Malfunction characteristics: during loading, the bucket does not automatically turn upward. However, after the bucket is taken back, it automatically turns downward. Possible reasons: According to the malfunction characteristics, the bucket does not automatically turn upward, but after the bucket is taken back, it automatically turns downward, which indicates that the sealing members of the bucket cylinder are not damaged. If the sealing members of the cylinder are damaged, usually the bucket will turn upward and downward automatically, so the internal leakage of the cylinder can be eliminated at the first step 1. The pressure of the large chamber overload valve is too low. 2. Sealing members of the large chamber overload valve are damaged. Inspection steps or actions: 1. A pressure meter shall be installed to measure if the large chamber overload pressure of the bucket cylinder is too low. Usually the large chamber overload pressure shall be set at 18MPa. 2. The large chamber overload valve shall be disassembled to check if the sealing members are damaged.

Malfunction case 5-3-04: During loading, the bucket automatically turns upward when it hits a hard object, and after the bucket is taken back, it automatically turns downward. Malfunction characteristics:, the bucket not only automatically turns upward during loading, but also automatically turns downward after the bucket is taken back. Possible reasons: According the malfunction characteristics, the bucket automatically turns upward during loading and automatically turns downward when the bucket is taken back. Such phenomenon indicates that the sealing members of the bucket cylinder may be damaged, which causes the pressure oil to circulate between the large and small chambers. 1. The overload pressure of the large and small chambers is adjusted too low. 2. The sealing members of the overload valves of the large and small chambers are damaged. 3. The sealing members and piston of the bucket cylinder are loose. Inspection steps or actions: 1. A pressure meter shall be installed to measure if the overload pressure of the large and small chambers of the bucket cylinder is adjusted too low. The requirements for the overload pressure of large and small chambers are: 18Mpa for large chamber and 12Mpa for small chamber. 2. The overload valves of the large and small chambers of the distribution valve shall be disassembled to check if the sealing members are damaged. 3. The sealing members and piston of the bucket cylinder shall be checked to see if they are loose.

Malfunction case 5-3-05: The bucket automatically turns downward when it is taken back, and the boom also 45

Chapter 5 Troubleshooting Working hydraulic system

automatically lowers after it is lifted Malfunction characteristics: both the bucket cylinder and boom cylinder have internal leakage. Possible reasons: Usually the bucket cylinder and boom cylinder do not have damaged sealing members simultaneously. However, there is possibility that damaged components may lead to damage of multiple cylinders, but in most cases, the malfunction is caused by improper use of oil or internal leakage. 1. Improper use of oil 2. Oil inlet pipes of working pump and steering pump are loose. 3. Distribution valve has internal leakage. 4. Sealing members of the hydraulic cylinder are damaged. Inspection steps or actions: 1. The hydraulic oil usage shall be checked, including usage time, oil specification, etc. 2. The hydraulic system shall be checked to see if a great amount of air enters the system. 3. The fit clearance between the slide valve bore and the slide valve rod of the distribution valve shall be checked to see if it is too large. 4. The bucket cylinder and boom cylinder shall be checked to see if the sealing members are damaged and if the piston is loose.

Malfunction case 5-3-06: the boom automatically lowers after it is lifted Malfunction characteristics: the boom automatically lowers at a high speed after it is lifted, but the bucket cylinder is normal. Possible reasons: The bucket cylinder and boom cylinder share the same oil. The bucket cylinder never leaks internally, so probably the malfunction does not stem from oil, but other reasons of the distribution valve and boom cylinder shall be extensively checked. 1. The sealing members of the distribution valve leaks internally after being damaged. 2. The fit tolerance between the slide valve bore and the slide valve rod of the distribution valve is too large. (Usually new valves may leak internally) 3. The sealing members of the boom cylinder are damaged or the piston is loose. Inspection steps or actions: 1. The sealing members of the slide valve link of the distribution valve shall be checked to see if they are damaged. (See Figure 5-12)

46

Chapter 5 Troubleshooting Working hydraulic system

Distribution valve

Figure 5-12: distribution valve and its installation position 2. The fit clearance between the slide valve bore and slide valve rod of the distribution valve shall be checked to see if it is too large. 3. The boom cylinder shall be checked to see if the sealing members are damaged or the piston and the piston rod are damaged by pulling.

Malfunction case 5-3-07: Lifting of bucket and boom is powerless Malfunction characteristics: no matter how much the oil temperature is, the lifting of bucket and boom is power and the lifting speed is low. Possible reasons: 1. The oil deteriorates or the added oil does not comply with the specified requirements or oil of different specifications is mixed together. (If the oil does not comply with requirements, usually it will lead to high temperature of the hydraulic oil) 2. The air filter element is blocked. 3. The oil-suction filter screen is blocked or the oil-suction rubber pipe becomes flat, which affects the oil suction during operation. 4. The distribution valve leaks internally. 5. The pressure of working pump or distribution valve is too low. 6. The sealing members of the bucket cylinder or boom cylinder are worn out or damaged. Inspection steps or actions: 1. The cleanness of oil shall be checked to see if it deteriorates or complies with the requirements. Usually No.46 hydraulic oil shall be used. However, at cold regions, No.40 low-freezing hydraulic oil shall be used. 2. The air filter element (hydraulic oil tank cover) shall be checked to see if it is blocked. 3. The oil suction and oil return filter screen of the hydraulic oil tank shall be checked to see if they are blocked, and at the same time, the oil suction rubber pipe of working pump shall be checked to see if it becomes flat. 4. The valve core of distribution valve shall be disassembled to check if the valve core and valve body have sand holes, etc., which may cause internal leakage. 5. The bucket cylinder and boom cylinder shall be checked to see if they have internal leakage. If there is 47

Chapter 5 Troubleshooting Working hydraulic system internal leakage, the bucket cylinder, boom cylinder shall be dismounted to check if the sealing members, piston and piston rod are damaged. 6. A pressure meter shall be installed to check if the pressure of distribution valve is adjusted improperly or the safety valve is damaged so as to confirm if the working pump leaks internally.

48

Chapter 5 Troubleshooting Pilot control system

5-4.Malfunction cases of the pilot control system:

5-4-01.Lifting of boom is powerless (I).................................................................................................................[48] 5-4-02.Lifting of boom is powerless (II) ....................................................................................................... [48] 5-4-03.Lifting of boom is powerless (IIII)....................................................................................................... [49] 5-4-04.Lifting of boom is powerless (IV)........................................................................................................[49] 5-4-05.Lifting of boom is powerless (V).........................................................................................................[49] 5-4-06.Lifting of boom is powerless (VI)........................................................................................................[50] 5-4-07.Lifting of boom is powerless (VII).......................................................................................................[50] 5-4-08.Boom cylinder automatically moves downward rapidly................................................................... [50] 5-4-09.Bucket cylinder automatically lowers too rapidly (I)......................................................................... [51] 5-4-10.Bucket sometimes automatically turns upward .............................................................................. [52] 5-4-11.Bucket cylinder automatically lowers too rapidly (II)........................................................................ [52] 5-4-12.Unable to realize floating function..................................................................................................... [52] 5-4-13.Control joystick of the pilot valve cannot be gripped properly at the extreme position ............. [53]

Malfunction case 5-4-01: lifting of boom is powerless (I) Malfunction characteristics: the working pump releases big noise and there are a great amount of bubbles in the oil. Possible reasons: The oil inlet pipe of the working pump is loose, so air enters into the system. Inspection steps or actions: The oil inlet rubber pipe of the working pump shall be checked to see if it is loose. (See Figure 5-13: working pump and its installation position)

Working pump

Figure 5-13

Malfunction case 5-4-02: lifting of boom is powerless (II) Malfunction characteristics: the oil temperature rises rapidly; while the throttle becomes bigger, the boom is elevated more slowly. Possible reasons:

49

Chapter 5 Troubleshooting Pilot control system The oil-inlet rubber pipe or the oil-suction filter element of the working pump is blocked, which causes unsmooth oil supply. Inspection steps or actions: The filter screen of the hydraulic oil tank and the oil suction rubber pipe of the working pump shall be replaced or cleaned.

Malfunction case 5-4-03: lifting of boom is powerless (III) Malfunction characteristics: the hydraulic oil temperature rises rapidly. Under serious circumstances, the oil turns black. Possible reasons: 1. Oil is used improperly, oil is too thick or air filter element is blocked, which causes oil suction difficulty. 2. The safety valve of distribution valve is stuck. 3. The engine does not provide sufficient power, the air filter element of the engine is blocked or the fuel oil has quality problems. Inspection steps or actions: 1. The air filter element shall be cleaned, or the oil shall be replaced with oil that complies with requirements. (At ordinary regions, No.46 hydraulic oil shall be used. At cold regions, No.46 low-freezing hydraulic oil shall be used.) 2. The safety valve of distribution valve shall be cleaned or replaced.

Malfunction case 5-4-04: lifting of boom is powerless (IV) Malfunction characteristic: the system pressure is not sufficient, and the working pump releases big noise. Possible reasons: 1. The working pump leaks internally and is not able to provide the pressure oil needed for normal operation. 2. The sealing members of the main safety valve of the distribution valve are damaged, which causes insufficient system pressure. 3. The hydraulic oil quantity is not sufficient or the oil suction rubber pipe becomes flat, which causes the large noise, or the distribution valve rod is adjusted to an incorrect position. Inspection steps or actions: 1. The system pressure shall be re-adjusted or the main safety valve shall be replaced. 2. The working pump shall be replaced. 3. The system shall be re-adjusted.

Malfunction case 5-4-05: lifting of boom is powerless (V) Malfunction characteristics: with the rise of oil temperature, the lifting capacity continues to decline, and the automatic downward movement of boom cylinder and bucket cylinder is obvious. Possible reasons: 1. Oil is used improperly, or oil is used for too long, so the oil deteriorates and causes the oil to be too thin. 2. The distribution valve leaks internally or the cylinder leak internally. 3. The sealing members of the bucket cylinder are damaged, which causes the pressure oil to circulate 50

Chapter 5 Troubleshooting Pilot control system between the large and small chambers. Inspection steps or actions: 1. The oil usage shall be checked and the oil shall be replaced if necessary. (Under normal circumstances, the hydraulic oil shall not be used over 1,200 hours) 2. The sealing members of the distribution valve shall be replaced. 3. The sealing members of the hydraulic oil cylinder shall be replaced.

Malfunction case 5-4-06: lifting of boom is powerless (VI) Malfunction characteristics: the pressure of the hydraulic system is normal, but the steering feels heavy. Possible reasons: 1. The working pump leaks internally or the valve core of the priority valve is stuck, which causes the oil interflowing to the hydraulic system to decline significantly. 2. The oil supply valve malfunctions. Inspection steps or actions: 1. The priority valve shall be cleaned or the working pump shall be replaced. 2. A pressure meter shall be installed to measure the oil outlet pressure of the oil supply valve when the boom moves. An excess low pressure indicates that the oil supply valve malfunctions.

Malfunction case 5-4-07: lifting of boom is powerless (VII) Malfunction characteristics: system pressure is normal but lifting is powerless Possible reasons: 1. Oil is not used properly, oil is too thick, or oil tank filter screen is blocked. 2. The valve core of pilot valve is stuck by contaminants or the internal discharge is too large, which causes that the pilot valve is unable to provide normal pressure oil to push the slide valve rod of the distribution valve. 3. The slide valve rod of the distribution valve is stuck, so the normal corresponding opening cannot be opened according to requirements. 4. The boom cylinder leaks internally. 5. The efficiency of the working pump declines. Inspection steps or actions: 1. The filter element of the hydraulic oil tank shall be cleaned and the hydraulic oil shall be replaced. 2. The pilot valve shall be cleaned and the relevant damaged components such as sealing members, etc. shall be replaced. 3. The slide valve rod of the hydraulic-control multiple unit valve shall be checked to see if it is stuck by contaminants. 4. The boom cylinder shall be checked to see if the piston and cylinder barrel are damaged by pulling or the sealing members are damaged. 5. The working pump shall be replaced.

Malfunction case 5-4-08: the boom cylinder automatically moves downward rapidly Malfunction characteristics: the bucket cylinder does not have obvious automatic downward movement 51

Chapter 5 Troubleshooting Pilot control system Possible reasons: 1. The valve core of the lowering valve that links the pilot valve and the boom is stuck. 2. The slide vale rod that links the distribution valve and the boom is stuck. 3. The boom cylinder leaks internally. Inspection steps or actions: 1. The control rod that links pilot valve and boom shall be checked to see if it is stuck and cannot return to the middle position. The stuck will cause the large chamber that links hydraulic-control multiple unit valve and boom to be slightly opened, so the oil of the large chamber of the boom cylinder leaks back to the oil tank. 2. The control rod that links pilot valve and boom is able to return to the middle position, but the slide valve rod that links hydraulic-control multiple unit valve and boom is stuck by contaminants and cannot be closed completely, so the oil of the large chamber of the boom cylinder leaks through the oil inlet of the multiple unit valve back to the oil tank 3. The sealing members of the boom cylinder are damaged, so the internal leakage is too large. The sealing members shall be replaced.

Malfunction case 5-4-09: The bucket cylinder automatically lowers too rapidly (I) Malfunction characteristics: during operation, when the bucket contacts hard objects, it will not automatically turns upward, and the boom cylinder will not automatically move downward obviously. Possible reasons: 1. The valve core that links pilot valve and bucket is stuck. 2. The large chamber overload valve that links the multiple unit valve and bucket is stuck or the pressure is set too low. (See Figure 5-14: multiple unit valve and its installation position)

Multiple unit valve

Figure 5-14 3. The slide valve rod that links multiple unit valve and bucket is stuck. Inspection steps or actions:

52

Chapter 5 Troubleshooting Pilot control system 1. The pilot valve is cleaned. 2. The pressure of the large chamber overload valve of the multiple unit valve shall be re-adjusted, or the sealing members shall be replaced. 3. The multiple unit valve shall be cleaned.

Malfunction case 5-4-10: the bucket sometimes automatically turns upward Malfunction characteristics: During operation, the bucket automatically turns upward when it contacts hard objects, but the bucket does not automatically turns downward after it is taken back, and the boom cylinder does not automatically lowers obviously. Possible reasons: 1. The valve core that links pilot valve and bucket is stuck. 2. The small chamber overload valve that links the multiple unit valve and bucket is stuck or the pressure is set too low. 3. The slide valve rod that links multiple unit valve and bucket is stuck. Inspection steps or actions: 1. The pilot valve shall be cleaned. 2. The pressure of the large chamber overload valve of the multiple unit valve shall be re-adjusted, or the sealing members shall be replaced. 3. The multiple unit valve shall be cleaned.

Malfunction case 5-4-11: The bucket cylinder automatically lowers rapidly (II) Malfunction characteristics: During operation, the bucket automatically turns upward when it contacts hard objects, but the bucket does not automatically turns downward after it is taken back, and the boom cylinder does not automatically lowers obviously. Possible reasons: 1. The large chamber and small chamber overload valves that link the multiple unit valve and bucket are stuck or the pressure is set too low. 2. The clearance between the slide valve rod (that links multiple unit valve and bucket) and the valve body is too large, which causes internal leakage. 3. The oil seal of the bucket cylinder is worn out or damaged, which causes the pressure oil to circulate between the large chamber and small chamber. Inspection steps or actions: 1. The multiple unit valve and overload valve shall be cleaned and the pressure shall be re-adjusted. (18MPa for large chamber and 12MPa for small chamber) 2. The multiple unit valve shall be replaced. 3. The sealing members of the bucket cylinder shall be replaced.

Malfunction case 5-4-12: unable to realize floating function Malfunction characteristics: when the control joystick is used to place floating devices, the devices cannot 53

Chapter 5 Troubleshooting Pilot control system realize the floating function, but other functions are not affected. Possible reasons: 1. After the K-opening cone valve at the bottom of the small chamber that links multiple unit valve and boom is blocked, the small chamber oil of the boom cylinder cannot flow through the pilot valve to the oil tank. 2. The sequence valve inside the pilot valve is stuck, so the small chamber oil of the boom cylinder cannot flow to the oil return chamber after entering the pilot valve (sequence valve). Inspection steps or actions: 1. The K-opening cone valve at the bottom of the small chamber that links multiple unit valve and boom shall be cleaned. 2. The sequence valve (inside 2C opening) inside the pilot valve shall be cleaned.

Malfunction case 5-4-13: The control joystick of the pilot valve cannot be gripped properly at the extreme position. Malfunction characteristics: When the control joystick is at its maximum angle during the lifting and lowering of boom and the upward turning of bucket, it cannot be gripped by the electromagnet, but will rebound back to the middle position automatically. Possible reasons: 1. The power is not turned on or has poor contact. 2. The components of the electromagnet coil of the pilot valve are damaged. Inspection steps or actions: 1. The contact of the electric system shall be checked. 2. The components of electromagnet coil shall be replaced.

54

Chapter 5 Troubleshooting Steering hydraulic system

5-5. Malfunction cases of the steering hydraulic system: 5-5-01. Steering seeming sluggish (I).................................................................................................................. [54]

5-5-02. Steering seeming sluggish (II) ..................................................................................................... [54] 5-5-03. Steering seeming heavy................................................................................................................. [54] 5-5-04. Steering failure or no steering........................................................................................................[55] 5-5-05. Idle stroke in steering, and a free swing at an angle in the direction.......................................[55] 5-5-06. Steering wheel kickback................................................................................................................. [56] 5-5-07. Steering wheel swinging................................................................................................................. [56] 5-5-08. Steering wheel shaking...................................................................................................................[57] 5-5-09. Steering endless and idling............................................................................................................ [57]

Malfunction case 5-5-01: Steering seeming sluggish (I) Malfunction characteristics: Steering sometimes sluggish and sometimes not sluggish, without regularity. Possible reasons: 1. The monostable valve is sluggish, leading to inadequate fluid to the steering gear, causing instant heaviness and sluggishness of steering. 2.

Oil pollution, causing the steering spool and sleeve or the stator and rotor to be sluggish.

Inspection steps or treatment methods: 1. Clean. 2. Replace the fluid and clean the hydraulic system.

Malfunction case 5-5-02: Steering seeming sluggish (II) Malfunction characteristics: Steering sometimes sluggish, but regular, and sluggish each time rotating to the same angle. Possible reasons: 1. The steering shaft deformed. 2. The steering shaft bearing damaged. 3. Friction between the steering shaft and the steering gear front cover. 4. Friction between the steering spool and sleeve or the stator and rotor has friction. Inspection steps or treatment methods: 1. Replace the steering shaft. 2. Replace the bearing. 3. Re-install. 4. Replace the steering gear.

Malfunction case 5-5-03: Steering seeming heavy 55

Chapter 5 Troubleshooting Steering hydraulic system Malfunction characteristics: When the engine has a higher speed, steering will be lighter, and when the engine rotates at low speed, steering will be heavier. Possible reasons: 1. The engine idle speed is too low. 2. The drive axle differential damage results in the decrease of differential function of the left and right wheels during steering. 3. The oil is dirty. 4. Steering pressure adjusted too low. 5. Internal leakage from the steering gear is excessive. 6. Steering pump leaking or spline damage causes decline of steering pump efficiency. (The factors are usually affects lift arm lifting speed will decrease.) 7. Internal leakage of the steering cylinder. Inspection steps or treatment methods: 1. Adjust the engine idle speed. 2. Check the drive axle differential damage. 3. Replace the oil and clean or replace the filter. 4. Re-adjust the steering pressure. When the pressure cannot be increased, the reason can be judged preliminary to lie in the steering pump or relief valve. According to the actual situation, replace the steering pump or relief valve. 5. Check the clearance between the steering gear spool and the valve body, and If necessary, replace the steering gear. 6. Replace the steering cylinder seals, and check the piston for looseness.

Malfunction case 5-5-04: Steering failure or no steering Malfunction characteristics: Sudden steering failure or no steering, but the work hydraulic system working properly. Possible reasons: 1. The spring in the steering gear is broken. 2. Serious leakage from the stator and rotor in the steering gear. 3. The steering cylinder piston seals severely damaged or the piston fallen off. Inspection steps or treatment methods: 1. Dismount the steering gear and check the spring leaf, stator and rotor for meshing. 2. Check the steering cylinder.

Malfunction case 5-5-05: Idle stroke in steering, and a free swing at an angle in the direction Malfunction characteristics: During steering, some idle stroke may occur suddenly, or when the road is uneven, it will automatically deflect towards the direction of gravity.

56

Chapter 5 Troubleshooting Steering hydraulic system Possible reasons: 1. There is a lot of oil in the air. 2. The steering gear check valve (small ball) has not been completely closed. 3. More serious internal leakage in steering gear stator and rotor. 4. The steering cylinder piston seals are damaged or loose. 5. Steering gear overload valve pressure is below the pressure of the relief valve, or the seals and springs of the overload valve are damaged. 6. The return oil back pressure of the steering system is slightly low. Inspection steps or treatment methods: 1. Put the direction to the maximum angle (with the hands pulling the steering wheel), increase the engine throttle up to about 800 rpm for 5 seconds, repeat the operation two or three times at the maximum left and right angle so that oil bubbles and air in oil discharges the air into the oil tank through high pressure unloading. 2. Clean the steering gear. 3. Replace the steering gear. 4. Replace the steering cylinder piston seals and check the piston for tightness. 5. Re-adjust the steering system operating pressure and overload valve pressure. 6. Improve the oil return back pressure of the steering system.

Malfunction case 5-5-06: Steering wheel kickback. Malfunction characteristics: Steering wheel kickback during steering. Possible reasons: 1. The steering gear and the steering shaft installed and adjusted improperly. 2. The steering system oil flowing back. Inspection steps or treatment methods: 1. Reinstall the steering gear. 2. Replace or re-tighten the inlet check valve at the steering gear oil inlet.

Malfunction case 5-5-07: Steering wheel swinging. Malfunction characteristics: The steering wheel swinging during steering. Possible reasons: 1. The steering cylinder seal damaged; 2. Steering gear spool sluggish; 3. The steering gear damaged; Inspection steps or treatment methods: 1. Check the steering cylinder seal for damage, and replace any damaged one. 2. Check the steering gear for damage or the steering spool for sluggishness. In the event of damage or 57

Chapter 5 Troubleshooting Steering hydraulic system sluggishness, replace the steering gear.

Malfunction case 5-5-08: Steering wheel shaking. Malfunction characteristics: The steering wheel shaking during steering. Possible reasons: 1. Steering gear damage causing uneven oil circulation. Inspection steps or treatment methods: 1.Check the steering gear and if damaged, replace it.

Malfunction case 5-5-09: Steering endless and idling. Malfunction characteristics: Steering wheel idling and endless during steering Possible reasons: 1. Steering gear damaged. Inspection steps or treatment methods: 1. Check the steering gear and replace it if damaged.

58

Chapter V Troubleshooting Foot Brake System

5-6. Some failure symptoms of foot brake system: 5-6-01.Brake failure (I).................................................................................................................................. [58] 5-6-02.Brake failure (II)................................................................................................................................. [58] 5-6-03.Brake sluggish................................................................................................................................... [59]

Malfunction case 5-6-01: Brake failure (I) Malfunction characteristics: Insufficient atmospheric pressure. Possible reasons: 1. After the system air connection is loosened, a large mount of compressed gas leaks, resulting in brake failure. 2. The pressure it is set too low, and after frequent braking operations, pressure is difficult to achieve a normal brake pressure, resulting in brake failure. 3. The brake air pressure should be adjusted to 0.7-0.78MPa, and during braking, air pressure shall not be less than 0.4MPa. 4. Caused by decrease in the air pump efficiency. Inspection steps or treatment methods: 1. Check the air pump, unloading valve, gas cylinder, foot brake valve and booster pump set for inlet and outlet pipe fittings. 2. Re-adjust the air pressure, with the brake pressure adjusted between 0.7-0.78MPa. 3. Check the pump and replace the air pump if necessary.

Malfunction case 5-6-02: Brake failure (II) Malfunction characteristics: Brake air pressure is normal, but braking effect is poor, and usually more pronounced after heating, with brake fluid ejected from the booster pump. Possible reasons: 1. The booster pump spring sluggish or broken. 2. Booster pump seal damaged. 3. Brake fluid brake failing or not in line with braking requirements. 4. The brake pads do not meet the requirements or there is grease on the surface, causing skidding of brake pads and brake discs. 5. The brake fluid contains a large amount of air, resulting in the decreased braking performance. 6. The brake piston sluggish. 7. The brake system oil circuit jammed. 8. The brake disc having too high hardness. Inspection steps or treatment methods: 1. Disassemble the booster pump, clean the booster pump and replace the seals and springs. (As shown in Figure 5-08: pictures for booster pump and its installation location)

59

Chapter V Troubleshooting Foot Brake System

Booster pump

Figure 5-08 2. Replace the brake fluid, which shall be plant synthetic brake fluid, with Longking special 719 synthetic brake fluid required. (Brake fluids of different grades and specifications can not be mixed) 3. Confirm whether the brake pads comply with brake requirements, and replace them if not. 4. Clean the brake system, and as required, empty the air in the system. 5. Check the brake caliper piston for return flexibility. If necessary, dismount the corresponding brake calipers to ensure their flexible return. 6. Carry out a comprehensive inspection of brake lines. 7. Check whether the brake disc hardness is too hard. If yes, replace brake discs meeting the requirements.

Malfunction case 5-6-03: Brake sluggish Malfunction characteristics: Brake air pressure is normal, but after braking, the loader starts more difficultly and becomes sluggish, easily making the brake system to produce heat. Possible reasons: 1. The foot brake valve does not return. 2. The booster pump does not return. 3. The brake caliper piston does not return. 4. There is oil in the air. Inspection steps or treatment methods: 1. Generally, cleaning the foot brake valve can resume normal braking. (See Figure 5-09: Picture for foot brake valve and its installation location)

60

Chapter V Troubleshooting Foot Brake System

Foot brake valve

Figure 5-09 2. Disassemble the booster pump, and clean and replace the seals. 3. Disassemble the brake caliper, clean the brake the system, replace the piston seal and replace damaged pistons and brake fluid. 4. Discharge air from the brake caliper bolts.

61

Chapter 5 Troubleshooting Electrical system

5-7. Malfunction cases of the electrical system:

5-7-01.Machine failing to start (I)................................................................................................................ [61] 5-7-02.Machine failing to start (II)......................................................................................................................... [61]

5-7-03.Starting immediately after power-on ............................................................................................ [62] 5-7-04.Not charging.......................................................................................................................................[62] 5-7-05.Excessive charging...........................................................................................................................[62] 5-7-06.Insufficient charge or over-discharge.............................................................................................[63] 5-7-07.Thermometer not functioning.......................................................................................................... [63] 5-7-08.Thermometer pointer rising to the maximum................................................................................[63] 5-7-09.The horn not ringing..........................................................................................................................[64] 5-7-10.Wiper not working............................................................................................................................. [64] 5-7-11.Poor air-conditioning cooling effect................................................................................................ [64] 5-7-12.Table of electric wires of loaders and routing...............................................................................[65]

Malfunction case 5-7-01: Machine failing to start (I) Fault Feature: Starter not responding Possible reasons: 1. The fuse is blown. 2. Poor contacts of buttons, harnesses and connectors. 3. Insufficiency of battery voltage. 4. The motor magnetic switch coil burned out, or the start circuit faulted. Inspection and troubleshooting: 1. Replace the fuse. 2. Check switches, harnesses and connectors for condition (4 # line) 3. Replace the battery (when the battery voltage is lower than 12V, recharging shall be considered; when the battery voltage is lower than 10V, replace the battery, and recharge the removed battery with a special charger.) 4. Check the starting circuit or motor, and replace the magnetic switch.

Malfunction case 5-7-02: Machine failing to start (II) Malfunction characteristics: After the start button is pressed, a “click” sound can be heard from the motor, the engine will not run or can only turn one or two circles. Possible reasons: 1. The battery voltage insufficient. 2. The motor coil burned out.

62

Chapter 5 Troubleshooting Electrical system 3. The motor or engine flywheel ring gear damaged. Inspection and troubleshooting: 1. With a special discharge tester, measure the voltage of each battery, and remove and recharge the battery whose voltage is lower than 12V. 2. Short the motor terminal with the magnetic switch terminal, and If failing to start, replace the starter motor. 3. Replace the motor or engine flywheel ring gear.

Malfunction case 5-7-03: Starting immediately after power-on Malfunction characteristics: The engine will start when the start electric lock is not yet placed on “start” position. Possible reasons: 1. The ignition switch contacts stuck. 2. The motor magnetic switch contacts stuck. 3. Short circuit. Inspection and troubleshooting: 1. Replace the ignition switch. 2. Replace magnetic switch. 3. Check whether 4#, 8# and 82a# lines are shorted with other power cord. Note: If the circuit and the motor operate normally, and the diesel engine fan can also turn, check the engine oil and the mechanical system for failure.

Malfunction case 5-7-04: Not charging. Malfunction characteristics: Insufficiency of battery voltage. Possible reasons: 1. Poor contact of lines and connectors. 2. The generator belt slack. 3. The generator damaged. 4. The battery damaged. Inspection and troubleshooting: 1. Check whether the charge indicator is off after completion of startup, and if it is bright, check whether the connecting circuit from the generator to the battery is in good condition. 2. Check the generator belt for looseness and adjust the belt. 3. Replace the generator. 4. Replace the battery.

Malfunction case 5-7-05: Excessive charging. Malfunction characteristics: Voltmeter pointer up to the highest point. Possible reasons: 63

Chapter 5 Troubleshooting Electrical system 1. The generator voltage too high. 2. The voltage regulator damaged. Inspection and troubleshooting: 1. Replace the generator voltage regulator.

Malfunction case 5-7-06: Insufficient charge or over-discharge. Malfunction characteristics: Battery voltage is low, and the electric appliance cannot work properly. Possible reasons: 1. The engine belt too loose; 2. Generator excitation coil and its mechanism fail; 3. Starting frequently and the engine working for a short time; 4. The night working too long or the vehicle electrical load too large; 5. At shutdown, the power switch not turned off. Inspection and troubleshooting: 1. Adjust the belt tension; 2. Replace generator or its excitation coil and resistance; 3. Minimize the number of starts; 4. At night work, minimize the number of starting the electrical equipment; 5. Be sure to turn off the main power switch when you shut down.

Malfunction case 5-7-07: Thermometer not functioning Malfunction characteristics: After power-on, the thermometer does not respond, regardless of cold or hot machines. Possible reasons: 1. The circuit broken. 2. The thermometer damaged. 3. The sensor thermistor damaged. Inspection and troubleshooting: 1. Check the 51 # line (for oil temperature) and 53 # line (for water temperature) for connection. Check 0 # line (for grounding) and 83 # line (for power supply) 2. Replace the thermometer. 3. Replace the sensor.

Malfunction case 5-7-08: Thermometer pointer rising to the maximum. Malfunction characteristics: After power-on, the thermometer pointer will directly rise to the maximum. Possible reasons: 1. Short circuit. 2. The sensor thermistor damaged. 3. Thermometer grounding wire broken. 64

Chapter 5 Troubleshooting Electrical system Inspection and troubleshooting: 1. Check 51 # line (for oil temperature) and 53 # line (for water temperature) for shorting or grounding with 0 # line (for ground wire) 2. Replace the sensor. 3. Check the thermometer ground wire for disconnection.

Malfunction case 5-7-09: The horn not ringing. Malfunction characteristics: The horn not ringing after the electric key turned on and the horn pressed. Analysis: 1. The fuse blown. 2. The horn relay bad or the coil burned out. 3. Poor contact of buttons, harnesses, connectors and ground wires. 4. Horn contacts bad or coils burned out. Inspection and troubleshooting: 1. Replace the fuse. 2. Replace the horn relay. 3. Check buttons, harnesses, connectors and ground wires for connection (power 16 # line, button 19 # line) 4. Replace the horn assembly.

Malfunction case 5-7-10: Wiper not working. Malfunction characteristics: After the wiper switch is turned on, the wiper does not work. Possible reasons: 1. The fuse blown. 2. Poor contact of switches, harnesses and connectors. 3. Wiper motor coils burned out. 4. The wiper lever not locked firmly. 5. The wiper’s main shaft is distorted or stuck or wiper lever is deformed. Inspection and troubleshooting: 1. Replace the fuse. 2. Check the switches, harnesses, connectors and ground wire for connection. 3. Replace the wiper motor assembly. 4. Lock the wiper lever nut. 5. Regulate main shaft motor or replace wiper motor and regulate wiper rod and transmission mechanism.

Malfunction case 5-7-11: Poor air-conditioning cooling effect. Malfunction characteristics: Air conditioning not working or not cooling. Possible reasons: 1. The fuse blown. 65

Chapter 5 Troubleshooting Electrical system 2. Poor contact of harnesses and connectors. 3. The air conditioning compressor not working (1) The belt too loose (2) The pressure switch wire on the drying bottle not connected properly or damaged (3) System pressure too low (high) For the normal pressure parameters, please see table below (4) The pipe damaged (5) The compressor damaged. (6) Refrigerant charged inadequately. 4. Failure of drying bottle. Inspection and troubleshooting: 1. Replace the fuse. 2. Check the wiring harness and connector for contact. (Total power 58 #, compressor power 38 #) 3. (1) Tension the belt (2) Check the wire on the pressure switch for connection or replace the drying bottle (3)

(appropriately discharged) refrigerant

(4) Detect the leakage location and replace the leaking part (5) Replace the compressor. 4. Replace the drying bottle and empty the system, and re-fill refrigerant (refrigerant type: R134a, filling amount: 950-1000g) Normal pressure of air-conditioning system Ambient temperature Value of low pressure gauge Value of high pressure gauge 0.2MPa±0.02MPa 1.4MPa±0.2MPa 25℃ 0.21MPa±0.02MPa 1.6MPa±0.2MPa 30℃ 0.23MPa±0.02MPa 1.8MPa±0.2MPa 35℃ 0.27MPa±0.02MPa 2.2MPa±0.2MPa 40℃ Conditions: compressor speed of 2000rpm; maximum air volume; humidity of 60%

5-7-12. Table of electric wires of loaders and routing

When repairing the failure of electrical system, refer to the following table to find a relevant line number: Table: Electric device name Combination headlight

Relevant line number 7#.14#.15#

Work light

6#.9#.56#

Rear headlight

11#.8#.29#

Circuit routing Fuse box 7 # → Six-hole jack → Combination switch (low beam 14 #, high beam 15 #) → Six-hole jack → Eight-hole socket (to wiring harness of the front frame) → Combination headlight Fuse box 6 # → Rocker switch (low beam 9 #, high beam 56 #) → Four-hole jack → Cab work light → Fuse box 11 # → Rocker switch (low beam 8 #, high beam 29 #) → Eight-hole jack → Connected to harness of rear frame) → Rear 66

Chapter 5 Troubleshooting Electrical system

Turn light

21#.22#.23#

Small light, instrument light

7#.12#.34#

Brake light

16#.17#

Horn

16#.19#

Wiper

32#.59#.62# (Return line)

Heater (air conditioning) Cooler

11#.58# 11#.27#

headlight (Fuse box 66 # → Flasher 21 # → Nine-hole jack → Turn signal switch (left 22 #, right 23 #) → Nine-hole jack Eight-hole jack (Connected to harness of rear frame) →Front turn light Eight-hole jack (Connected to harness of rear frame) → Rear turn light Fuse box 7 # → Six-hole jack → Combination switch → Six-hole jack → Twelve-hole jack → Instrument light (34 #) Rocker switch indicator (34 #) → Eight-hole jack (Connected to harness of front and rear frames 12 #) → Small light Fuse 16 # → Eight-hole jack → Brake light switch (17 #) → Brake light Fuse box 16 # → Eight-hole jack → Horn relay → Horn → 19 # Eight-hole jack → Twelve-hole Jack → Combination switch → Horn button → Grounding Return circuit: 32 # → Wiper return device 62 # Fuse box 32 # → Twelve-hole jack → Wiper switch (59 #) → Twelve-hole jack → Four-hole wiper jack → Wiper motor twelve-hole jack Fuse box 11 # → Rocker switch 58 # → Eight-hole jack (Connected to harness of rear frame) → Heater jack → Heater (air conditioning) Crisper 11 # → Rocker switch 27 # → Fan jack → Fan

67

Chapter 6 Main Parts

Chapter 6 Main Parts

Section 1 Hydraulic torque converter (YJ31502GA)....................................................................................[68] Section 2 Gearbox...................................................................................................................................................[86]

Section 3 Drive axle .................................................................................................................................. [120] Section 4 Air brake valve assembly..........................................................................................................[144] Section 5 Combination valve of oil-water separator (SH380D) ..........................................................[155] Section 6 Booster pump............................................................................................................................. [157] Section 7 Brake caliper (brake system)................................................................................................... [171] Section 8 Working pump............................................................................................................................ [178] Section 9 Distribution valve........................................................................................................................[192] Section 10 Lift arm cylinder........................................................................................................................[206] Section 11 Bucket cylinder.........................................................................................................................[214] Section 12 Priority valve............................................................................................................................. [222] Section 13 Steering gear............................................................................................................................[229] Section 14 Steering cylinder...................................................................................................................... [247] Section 15 Working hydraulic oil cooler...................................................................................................[249] Section 16 Air conditioning system.................................................................................................................... [253]

68

Chapter 6 Main parts Section 1 Hydraulic torque converter

Section 1 Hydraulic torque converter (YJ31502GA) Table of Contents 1 Structure and Functions.......................................................................................................... [68] 2 Testing and Adjustment...........................................................................................................[71] 3 Dismounting and Installation.................................................................................................. [72] 4 Disassembly and Repair......................................................................................................... [73]

1. Structure and functions Linked to the diesel engine, the torque converter automatically adjusts output torque and speed so that the loader can automatically change the speed and traction force depending on road conditions and resistance to adapt to different working conditions. After being putting into gear, the loader can realize automatic stepless speed change from starting gear to the highest speed of the top gear and ensure steady start and good acceleration performance. In case of a slope or unexpected barricade, the loader can automatically decelerate, increase traction force and drive past the barricade at any low speed without the need for gear shift. After reduction of external resistance, the loader can quickly accelerate for an increased working efficiency. During skimming operation, the loader can cut into material pile at a high speed and automatically decelerate with increasing resistance to improve the wheel-side traction force and ensure cut-in. Hydraulic torque converter is a non-rigid connected transmission device which is composed of several blade wheels. Using liquid as the transmission media, it features good vibration isolation and reduction performance, stabilizes transmission and improves service life of equipment; it transmits power via changing hydraulic momentum moment and automatically adapts to rotating speed and torque. It can improve the operating efficiency of machines and enhance the passing capacity of vehicles. The hydraulic torque converter is directly fixed on the flywheel cover of engine. The power input mode is spring disc input and the output mode is concentric output. The output terminal is flange.

Figure 6-1-01 The torque converter chiefly comprises three working wheels, namely pump impeller, turbine wheel and guide impeller, and its working chamber is filled with working oil. Pump impeller is designed to convert the mechanical energy of the engine into the kinetic energy of the liquid. Powered by the engine, the pump impeller rotates at the same speed, forcing the oil in the chamber to impact the turbine wheel at a huge speed and pressure. The turbine wheel absorbs and reverts the kinetic energy of liquid flow into mechanical energy, thus transmitting the dynamic force to output flange; the guide impeller is fixed and does not rotate. While impacting guide impeller blades, the liquid flow gives a torque to the guide impeller. 69

Chapter 6 Main parts Section 1 Hydraulic torque converter Since the guide impeller is fixed, it generates a counter torque that has an equal force in the opposite direction and transfers it to the turbine wheel via liquid flow, thus changing the output torque of the guide impeller. The blades of the three working wheels have given shapes and inlet/outlet angles so that the liquid can pass through different blade wheels according to the required flow passages and directions. Items Type of hydraulic torque converter Single-stage single-phase centrifugal turbine Direction of rotation (seen at the input end) Clockwise Maximum input speed 2400r/min Input power 38~105kW Working fluid 6# or 8# hydraulic transmission oil Outlet oil Normal 80~100℃ pressure Short time 120℃ Inlet oil pressure 0.45～0.65Mpa Outlet oil pressure 0.25～0.5Mpa Performance parameters Effective diameter D 315mm Maximum efficiency ηmax ≥0.82 Zero-speed torque ratio K0 3.45±5% Nominal torque MBgη 69.16±5% N.m

Inside the hydraulic torque converter, the flow channels of pump impeller 14, turbine 5 and guide wheel 11 make up the space for liquid circulation, and the aforesaid three components and pump impeller cover 6 form a closed container together. The power of engine is transmitted to pump impeller 14 via spring disc 3 and pump impeller cover. Under the effect of centrifugal force, the pump impeller transforms the mechanical energy of engine to the kinetic energy and pressure energy of working fluid to drive the turbine to rotate. Then the turbine transforms the liquid energy to mechanical energy again. Via the fixed guide wheel, the fluid that flows out of the turbine transforms part of the pressure energy to kinetic energy, increases the rotation degree of fluid and flows back to the entrance of the pump impeller. Such circulation forms the normal operation of hydraulic torque converter. The guide wheel increases the velocity circulation of the fluid at the entrance of the pump impeller, and consequently increases the output torque of the hydraulic torque converter and completes the “torque conversion”. The increasing degree of output torque depends on the condition at the exit of turbine, i.e. such change automatically adapts to the change of load. When the load increases, the output rotating speed automatically decreases, and the velocity circulation of fluid at the exit of turbine decreases, the velocity circulation of fluid at the entry of pump impeller increases, and the torque outputted by turbine increases simultaneously. On the contrary, when the load decreases, the output rotating speed automatically increases, and consequently the output torque decreases. This feature is the auto-adaptation of rotating speed and torque to external load. The guide wheel is fixed with guide wheel base 47 on shell 45. Pump impeller is fixed with pump impeller hub 49. On the pump impeller hub, there is a pump-driving gear 28 that meshes two pump-driven gears 26. The driven gears drive working pump and variable speed pump via two pump-driving shafts 20 and 23. The variable speed pump provides oil to shift valve and hydraulic torque converter of gearbox. The oil that enters hydraulic torque converter flows through the oil inlet chamber of the guide wheel base and the gap between bearing balls and enters the circulating circle of hydraulic torque converter from the exit of pump impeller, and then flows through the gap between the exit of turbine and the exit of guide wheel as well as the gap between turbine shaft 39 and guide wheel base, finally flows out of the shell through the oil outlet chamber of guide wheel base.

70

Chapter 6 Main parts Section 1 Hydraulic torque converter

Figure 6-1-02

No. 1 2 3 4 5 6 9 11 12 14 17 18 19 20 22 23 24 25 No. 26 28 35 37 38 39 41 42 44 45 46 47 48

No. of diagram YJ31502GA-01 YJ31502GA-03 YJ31505X-01 YJ31505X.02 YJ31502A.02 YJ31502GA-02 YJ31505X-06 YJ31502A-04 YJ31502GA-04 YJ31502F-06 YJ31502D-08 YJ31502D-09 YJ31502D.01 YJ31502A-14 YJ31502F.01 YJ31502D-11 YJ31502D-12 No. of diagram YJ31502D-13 YJ31502D-14 YJ31502C-09 YJ31502C-07 YJ31502D-15 YJ31502C-05 YJ31505C.04 YJ31502B-04 YJ31502C-10 YJ31502G-02 YJ31502A-13 YJ31502D-16 YJ31502A-09

List of parts Name Cover Transition disc Spring disc Spring disc assembly Turbine assembly Pump impeller cover Pressure plate of spring disc Guide wheel Cover plate Pump impeller Upper cover plate Paper gasket Vent plug 15276 Pump-driving shaft assembly (I) Spigot ring Pump-driving shaft assembly (II) Secondary separating plate Primary separating plate List of parts

Name Pump-driven gear Pump-driving gear Shaft sleeve Retainer ring Output flange Turbine shaft Back-pressure valve Paper gasket End cover Shell Sealing ring Guide wheel base Sealing ring 71

Chapter 6 Main parts Section 1 Hydraulic torque converter

49 51 53 54

YJ31502D-17 YJ31502A-10 YJ31502A-17 YJ31502F-05

Pump impeller hub Oil separation sleeve Baffle plate Cover plate

All the bearings and wearing parts Name

Bearing

Sealing ring

Quan tity

Installation position

4

End of pump-driving shaft

1

Output end of turbine shaft

1

Turbine assembly

1

Pump impeller hub

φ70×φ64.2×3

1

Turbine shaft

φ80×φ73.6×2.4

2

Guide wheel base

YJ31502A-1 5

320×3.55

2

Pump impeller, primary separating plate

GB/T3452.11992

140×2.65 185×3.55 190×3.55 140×3.55 40×2.65

1 1 1 1 1

Pump impeller hub Guide wheel base Guide wheel base Guide wheel base Output end of turbine shaft

SD70×95×12

1

Output flange end

B115×140×12D

2

Primary and secondary separating plate

Code

GB/T2 76-1994 GB/T296-19 94 YJ31502A-1 3 YJ31502A-0 9

O-shaped sealing ring

Framework oil seal of rotating shaft

JB/T2600-19 80 GB/T9877.11988

Specification 6012(60×95×1 8) 6312-RS(60×1 30×31) 6013(65×100× 18) 3212M(60×110 ×36.5)

2. Test and Adjustment 1. Management of working oil a. The torque converter shall use 6# or 8# hydraulic transmission oil, which is working oil and lubricating oil as well. During use, the oil shall be kept clean and separate from other types of oil. b. For first use of the new machine, the engine must be kept running at a low speed for several minutes in order that oil fills up all ducts and accessories. Before daily work, check the oil level of the speed changer. Insufficient oil level will cause oil pressure drop, low output power or overheated working oil. c. During initial use, oil filter shall be checked and cleaned each day. New oil shall be all used 60 hours after first use. After that, make oil replacement using new oil every 1000 hours and check the oil filter every 100 hours. If oil is found to contain water, metal dust or large quantities of impurities, it shall be replaced with new oil. d.Before oil replacement, all oil filters and pipes in the system shall be cleaned and any ineffective filters and pipes shall be replaced. 2. Oil pressure check When the engine operates under the braking condition at a speed of 1800r/min and oil temperature ranges 80~100℃, the outlet pressure of the torque converter shall be 0.25～0.31MPa. 3. Check the oil seals, pipe connections and valve fitting surfaces of torque converter and rule out any external leakage. 72

Chapter 6 Main parts Section 1 Hydraulic torque converter 4. Use of oil temperature During normal operation, the outlet oil temperature of torque converter is 80~100℃ and may reach 120℃ for a short period of time. If the oil temperature remains above 120℃ for long, it is advisable to stop operation and make the engine run idle. Stop the engine for an inspection when the oil temperature falls below 80℃. (5) Overhaul a. It is recommended that a major interval should be conducted every 3000 hours or one year (whichever comes earlier). b. Before repair, carefully read the disassembly and assembly procedure. c. Wearing parts including oil seals, O-rings and seal rings, though no damage is found after inspection, they must be replaced with new parts. Replacement parts shall be gotten ready before disassembly.

3. Dismounting and Installation 1. The connection between torque converter and engine adopts the hoisting method. First, hoist the torque converter by mounting No.2 transition disc onto the flywheel of engine , aim the core shaft head on the left side of pump impeller cover at the center hole of the flywheel of the engine, slowly push the shaft head into the hole, and then fix it with the spigot on wheel cover. Use 12 bolts to fasten the wheel cover to the wheel cover of flywheel of the engine. Then fasten the elastic plate to the transition disc through the window on the wheel cover. It is noted that no impurities shall be allowed to enter the shell during installation. Once any impurity enters the shell, the shell shall be disassembled to have the impurity cleared away before reinstallation. 2. Join all accessories and pipes according to the machine’s hydraulic system. (Lubrication pipe shall be connected at No.15) (see Figure 6-1-02). 3.Fill the torque converter with the required quantity of 6# or 8# hydraulic transmission oil. These two types of oil cannot be mixed up. 4. Start the engine and check its oil level under idle run. Make replenishment timely in case of insufficiency. 5. Check if the oil pressure is normal or if oil leakage exists. 6. Cleaning, check and replacement a. All metal parts shall be cleaned with gasoline or volatile industrial alcohol. No caustic soda solution may be used. b. Dry up the cleaned metal parts. Then smear them immediately with actually used hydraulic transmission oil. c. Check and make sure the mounting surface is free of gap, burr, scratch or impurities. Remove burrs or foreign matters with sand cloth or grind stone, and replace any parts found with big damage and noticeable scratch. d. Replace any cracked casting. e. Check if bearing race has any nick, indentation, crack, debris or excessive wear and tear of ball bearings. Make replacement for any identified defect. f. Check if bearings move freely. Make replacement if any bearing jams despite enough lubrication. g. Check if tooth profile of gear wheel is worn and distorted. Replace gear wheels if any such defect is found. h. Check if tooth face of gear wheel has any streak, burr or breakage. Replace the gear wheel if such defect cannot be removed with grind stone. i. Check if the spline has any flaking, scar, distortion or burr. Remove burrs with grind stone. Make replacement for any other damage. j. Check the wear and tear of contact area between pump impeller rim 49 and seal ring 48. Replace the pump impeller rim if groove wear is more than 0.15mm deep. (See Figure 6-1-02). 73

Chapter 6 Main parts Section 1 Hydraulic torque converter k. Check the wear and tear of contact area between guide impeller seat 47 and seal ring 46. Replace the guide impeller seat or bushing if groove wear is more than 0.15mm deep. l. The dimension of wear limit for contact area of seal lip is nominal dimension 100 plus 0.2mm.

4. Disassembly and repair During disassembly and assembly, spare parts must be kept clean and the operation shall be performed on work benches at the worksite free of dust and sand soil. (1) Disassembly of torque converter A-1 Dismount the bolts that connect the spring disc, and dismount the spring disc. (See Figure 6-1-03)

Spring disc

Figure 6-1-03 A-2 Dismount the bolts that connect cover and shell, and use the jackscrew hole on the cover to dismount the cover. (See Figure 6-1-04)

Shell Cover

Figure 6-1-04 A-3 Dismount the bolts that connect pump impeller cover and pump impeller, and use the jackscrew hole to dismount pump impeller cover. (See Figure 6-1-05) 74

Chapter 6 Main parts Section 1 Hydraulic torque converter

Pump impeller cover

Pump impeller

Figure 6-1-05 A-4 (see Figure 6-1-06) a. Dismount the bearing snap ring on the left side of turbine shaft, and dismount the support bearing of pump impeller cover. b. Dismount the bolts that fix the retainer ring on the left side of turbine shaft, and dismount the retainer ring. c. Dismount the turbine assembly from the turbine shaft. Turbine shaft Turbine assembly Retainer ring

Figure 6-1-06 A-5 Dismount retainer ring and guide wheel. (See Figure 6-1-07)

75

Chapter 6 Main parts Section 1 Hydraulic torque converter

Guide wheel Retainer ring

Figure 6-1-07 A-6 Dismount the bolts that connect the pump impeller and pump impeller hub, dismount baffle plate, and then dismount pump impeller. (See Figure 6-1-08) Pump impeller Baffle plate

Pump hub

impeller

Figure 6-1-08 A-7 (see Figure 6-1-09) a. Dismount the bolts that connect primary separating plate and shell, and use the jackscrew to separate the primary separating plate and shell. b. Dismount the components such as primary separating plate, secondary separating plate, pump impeller hub, bearing, oil seal, pump-driving gear, etc. from the shell. c. Dismount the aforesaid components.

76

Chapter 6 Main parts Section 1 Hydraulic torque converter

Primary separating plate

Secondary separating plate

Shell

Oil seal

Pump impeller hub

Bearing

Pump-driving gear Figure 6-1-09

A-8 Dismount nut, and then dismount retainer ring, output flange and shaft sleeve. (See Figure 6-1-10)

Output flange Retainer ring

Nut

Shaft sleeve Figure 6-1-10 A-9 Dismount the bolts that connect upper end cover and shell, and then dismount end cover together with oil seal 43 from the shell. (See Figure 6-1-11)

77

Chapter 6 Main parts Section 1 Hydraulic torque converter Shell End cover

Figure 6-1-11 A-10 Dismount retainer ring and O-shaped ring. Use a copper bar to knock the turbine shaft from the left side, and then dismount the turbine shaft together with bearing from the guide wheel base hole. (See Figure 6-1-12) Turbine shaft Bearing

Retainer ring

Guide wheel base Figure 6-1-12 A-11 (see Figure 6-1-13) a. Dismount guide wheel base from shell. b. Dismount upper cover plate.

78

Chapter 6 Main parts Section 1 Hydraulic torque converter Upper cover plate

Guide wheel base

Figure 6-1-13 A-12 (see Figure 6-1-14) A.Dismount retainer ring. Use the M12 screw hole in the middle of pump-driving shaft assembly to dismount the pump-driving shaft assembly together with bearing from the shell. b. Dismount back-pressure valve from the shell. Shell Bearing Pump-driving shaft Shell

Bearing Pump-driving shaft Figure 6-1-14 A-12 Dismount the pump-driven gear together with bearing from the shell. (See Figure 6-1-15)

79

Chapter 6 Main parts Section 1 Hydraulic torque converter Shell

Pump-driven gear Figure 6-1-15 (Disassembly is completed) (2) Repair the torque converter B-1 (see Figure 6-1-16) a. Install the bearing onto the pump-driven gear, and then install the retainer ring to fix the bearing. b. Install the components of Step (a) onto the corresponding positions of the shell. c. Install the bearing and spacer onto the pump-driving shaft assembly. d. Install the components of Step (c) onto the shell, and then install the retainer ring and spigot ring.

Shell

Bearing

Spigot ring Bearing

Pump-driven gear

Pumpdriving shaft

Retainer ring

Figure 6-1-16

80

Chapter 6 Main parts Section 1 Hydraulic torque converter B-2 After installing the bearing and sealing ring (see Figure 6-1-02) onto the turbine shaft, install the turbine shaft onto the guide wheel base, and then install retainer ring, O-shaped ring and sealing ring (see Figure 6-1-02). Install the aforesaid components onto the shell, and then install O-shaped ring. (See Figure 6-1-17)

Guide wheel base Bearing

Retainer ring

Turbine shaft Figure 6-1-17 B-3 (see Figure 6-1-18) a. Install oil seal onto the end cover, and then install the end cover together with guide wheel base on the shell. b. Install shaft sleeve, output flange, retainer ring and fixing bolt. End cover

Shaft sleeve

Output flange

Guide wheel Retainer base ring

Shell

Retaining nut

Figure 6-1-18

B-4.

(see Figure 6-1-19)

a. Install the oil seals into the holes at the corresponding positions on the primary separating plate and secondary separating plate, and then fix the primary separating plate and secondary separating plate together. b. Install bearing and O-shaped ring onto the pump impeller hub, install the pump impeller onto the 81

Chapter 6 Main parts Section 1 Hydraulic torque converter bearing, and then connect pump impeller and pump impeller hub. c. Fix the components of Step (b) and Step (a) together, install the pump-driving gear onto the pump impeller hub, and then install the retainer ring.

Bearing

Primary separating plate

Secondary separating plplate

Retainer ring

Pump impeller

Pump impeller hub

Pump-driving gear

Figure 6-1-19 B-5

(see Figure 6-1-20)

a. Install the components of Step (c) of B-4 onto the shell and guide wheel base. (Note: prevent the sealing members from being damaged). b. Install the guide wheel onto guide wheel base, and then install the retainer ring.

Guide wheel

Guide wheel base

Retainer ring Shell

Figure 6-1-20 B-6. Install the support bearing of pump impeller cover onto the turbine assembly, install the fixing retainer ring, install the turbine assembly onto the turbine shaft, and then install the retainer ring and fixing bolt. 82

Chapter 6 Main parts Section 1 Hydraulic torque converter (See Figure 6-1-21) Turbine assembly Support bearing Fixing bolt

Retainer ring

Fixing retainer ring Figure 6-1-21

B-7 Install the O-shaped ring onto the pump impeller, and fix the pump impeller cover and pump impeller together. (See Figure 6-1-22) Pump impeller Pump impeller cover

Pump impeller

Pump impeller cover Figure 6-1-22

B-8 Install the cover onto the shell. (See Figure 6-1-23)

83

Chapter 6 Main parts Section 1 Hydraulic torque converter Cover

Cover

Shell

Figure 6-1-23 B-9. Install the spring disc assembly. (See Figure 6-1-24) Shell Spring disc

Shell

Figure 6-1-24

B-10. Install paper gasket 18 (see Figure 6-1-02) and upper cover plate, and then install vent plug and lifting ring. (See Figure 6-1-24)

84

Chapter 6 Main parts Section 1 Hydraulic torque converter

Lifting ring

Upper cover plate

Figure 6-1-25

B-11. Install paper gasket 42 (see Figure 6-1-02), back-pressure valve and pipe close. (See Figure 6-1-26)

Back-pressure valve

Figure 6-1-26

85

Chapter 6 Main parts Section 1 Hydraulic torque converter Note: the list of needed tools, suppliers and equipment is as follows: (1) Internal hexagonal wrench; (2) Socket wrench; (3) Air wrench; (4) Internal and external snap ring plier; (5) Puller； (6) Crow bar; (7) Hammer; (8) Iron bar (diameter=8mm, length=150mm); (9) Container, brush and cleaning fluid for cleaning parts; (10) Copper bar (diameter=10mm, length=400mm); (11) Grease.

86

Chapter 6 Main parts Section 2 Gearbox Section 2 Gearbox Table of Contents 1 Structure and Functions.......................................................................................................... [86] 2 Testing and Adjustment...........................................................................................................[87] 3 Dismounting and Installation.................................................................................................. [88] 4 Disassembly and Repair......................................................................................................... [94]

1. Structure and Functions The gearbox comprises Main Parts including box body, box cover, forward-reverse gear clutch assembly, I & III gear clutch assembly, II gear clutch assembly, output shaft assembly, filter assembly and control valve, and each gear clutch assembly comprises a number of driven clutch discs and driving clutch discs, piston assembly, gear wheels, shafts, seal rings, and retracting springs. To put the machine into a particular gear, the operator shall cause the two clutches of the corresponding direction and speed gears to form a gear ratio to transmit torque. During gear shift, driven and driving clutch discs of the corresponding gear is compacted by piston under the influence of working oil pressure in an axial direction. Driven and driving clutch discs loosen when the piston returns under the influence of retracting spring.

Figure 6-2-01 Transmission route of each gear is shown below (See Figure 6-2-02): Forward gear I: Engage F and I clutches Input→Z1→Z7→Z4→Z10→Z11→Z12→Front/rear axle output Forward gear II: Engage F, II clutches Input→Z1→Z7→Z5→Z9→Z11→Z12→ Front/rear axle output Forward gear III: Engage F, III clutches Input→Z1→Z7→Z6→Z8→Z11→Z12→Front/rear axle output Reverse gear I: Engage R, I clutches Input →Z2→Z13→Z3→Z4→Z10→Z11→Z12→Front/rear axle output Reverse gear II: Engage R, II clutches Input →Z2→Z13→Z3→Z5→Z9→Z11→Z12→Front/rear axle output Reverse gear III: Engage R, II clutches Input →Z2→Z13→Z3→Z6→Z8→Z11→Z12→Front/rear axle output 87

Chapter 6 Main parts Section 2 Gearbox

Schematic diagram of ZL30E.5G gearbox Figure 6-2-02

2. Testing and Adjustment Since torque converter and gearbox are two interrelated assemblies as power transmission and output, the content of “gearbox test and adjustment” as described in this section includes torque converter. The variable speed pump gets oil from the oil suction opening of the gearbox, and the said oil suction opening has a coarse filter. Oil obtained from oil pump is treated by the coarse filter before being sent to the control valve. When oil pressure reaches a particular value, open the pressure regulating valve. Some of oil flows into the torque converter, and some flows into the gear shift control valve. The gear shift control valve conducts gear shift by controlling the oil charge and drain of each gear shift clutch, namely the engagement and disengagement of such clutches. When the oil pressure of the torque converter reaches a particular value, open the output pressure valve of the torque converter to cause oil to pass through the cooler and flow into the lubricating system of the gearbox. ① During operation, check the connection of each oil line for closeness every day, and if oil leakage is found, repair it in time. ②The arrow shown above is a sight glass for torque converter. During shutdown, you can open the sight glass cover to check inside condition or looseness of the fasteners, without allowing the ingress of any foreign matter into the machine. The machine cannot be started until the sight glass cover and gaskets are replaced and there is no abnormal condition. ③ Oil filter 1 is equipped with a signal sender, which may give out an alarm automatically once the internal filter is jammed, and when there is any alarm prompt, the machine should be stopped to replace accessories or assemblies. 88

Chapter 6 Main parts Section 2 Gearbox ④The torque converter oil pressure and oil temperature are monitored through instruments. If abnormal condition is discovered, first check the oil filter 2, replace the filter screen or assembly. If failure remains, check other locations. ⑤Before starting the engine, adjust the working oil level of the torque converter and the gearbox. Check the two drain plugs on the right of the gearbox, with the upper plug representing the maximum oil level and the lower plug representing the minimum oil level. Under normal conditions, oil should be between the upper and lower oil levels. If oil is too much, some oil shall be released from the oil pan of the gearbox, if too little, some oil shall be added from the oil filler of gearbox. ⑥ Monitoring and adjustment of the working oil pressure of the torque converter and gearbox. The pressure at the inlet and outlet of monitoring and adjusting torque converter has been adjusted in the manufacturer; for the working oil pressure of the gearbox, after operation of the engine, the pressure meter shall point the range of 1.5~1.7MPa, and in case of abnormal condition, inspection shall be conducted. ⑦ Adjustment of working oil temperature of torque converter and gearbox The maximum oil temperature for general tasks and driving must not exceed 120 ℃ , and if this figure is exceeded, the machine shall be stopped for cooling and inspection. After the gearbox passes the breaking-in period, oil replacement shall be made generally after 600 hours; however, if oil is deteriorated or mixed with impurity, it shall be cleaned, checked and replaced with new oil of required grade.

Sight window

Pipeline from control valve to torque converter

Pipeline from oil filter to control valve

Oil filter

Return oil pipe Oil suction pipe of variable speed pump

Pipeline from variable speed pump to oil filter

Pipeline from torque converter to cooler

Oil outlet pipe of cooler

Figure 6-2-03

3. Dismounting and Installation

The disassembly and installation of the gearbox is detailed below: (I)) Position of gearbox on the product

89

Chapter 6 Main parts Section 2 Gearbox Gearbox

Torque converter

Figure 6-2-04 As shown in Figure 6-2-04, torque converter assembly is connected to gearbox assembly through upper transmission shaft; front and rear output flanges of the gearbox are connected to front and rear drive axles through transmission shaft; torque converter is connected to the diesel engine through internal and external reaming. (II) Disassembly steps (1) Disassemble the cab in the following steps:

Figure 6-2-05

90

Chapter 6 Main parts Section 2 Gearbox

Figure 6-2-06

Figure 6-2-07 a. Hoist up the cab with a traveling crane and hoisting device. Ropes shall be straightened up but not tightly stretched; b. Dismount nylon lock nut, pin and gasket; c. Hoist the cab and put it at a safe place; d. Remove the shock pad assembly;

①Hoisting safety precautions: While hoisting the cab, the hoisting device must be hung at a reasonable position to prevent overturn; ②Conduct the hoisting operation steadily and make sure personnel nearby stay within a safe range. (2) Disassemble the gearbox assembly in the following steps:

91

Chapter 6 Main parts Section 2 Gearbox

Figure 6-2-08 a. Use the wrench to dismount bolts and gaskets connecting the bracket of oil filling pipe assembly to the frame. b. Use the wrench to dismount hoses and steel pipes connected to the variable speed pump (Note: Before dismounting, open the oil drain plug at the bottom of gearbox to drain off transmission oil. Then loosen the joints of steel pipe and hose to be dismounted. Put cotton cloth at the dismounting joint and strike lightly the joint of steel pipe or hose to be dismounted. After releasing all pressure, remove the steel pipe or hose). Bolt M16×110

Figure 6-2-09 c. As shown in Figure 6-02-09, use pneumatic wrench and supporting sleeve to dismount four (4) M16×110 bolts, nuts and washers (M16 flat washer and self-locking nut) connecting the gearbox to the mounting base of the gearbox on the rear frame. 92

Chapter 6 Main parts Section 2 Gearbox

Bolt M12×1.5×35, M12×1.5 self-locking nut Gearbox

Middle transmission shaft

Intermediate support Rear transmission shaft

Front transmission shaft

Bolt M14×1.5×42, M14×1.5 self-locking nut

Bolt M14×1.5×60, M14×1.5 self-locking nut

Figure 6-2-10 e. As shown in Figure 6-2-10, use pneumatic wrench and supporting sleeve to dismount four (4) M14×1.5×60 bolts and self-locking nuts connecting the gearbox to the central transmission shaft; to dismount four (4) M14×1.5×42 bolts and self-locking nuts connecting the gearbox to the rear transmission shaft. f. Use pneumatic wrench and supporting sleeve to dismount M12×1.5×35 bolts and self-locking nuts connecting the gearbox to the upper transmission shaft. g. Use the specialized hoisting device to lift the gearbox assembly to the given bracket. (III) Commissioning requirement Commissioning, if needed, shall be conducted by designated personnel; (IV) Installation (1) Install the gearbox in the following steps: a. Use the specialized lifting device to hoist the gearbox to the frame; b. Mount bolts and nut connecting upper transmission shaft, front and rear transmission shafts to the gearbox; c. Use bolts to fix the gearbox on the gearbox mounting base. Note: Keep clean during installation. (2) Install the cab in the following steps: a. Before hoisting, check if all interior trims of cab assembly are intact; b. Preassemble back plate and shock pad. Mount the shock pad assembly (upper components) on the pedestal of the cab, with hole sites aligned, as shown in Figure 6-2-11;

93

Chapter 6 Main parts Section 2 Gearbox

Figure 6-2-11

Figure 6-2-12 c. As shown in Figure 6-2-12, use a special lifting device and traveling crane to lift the cab at a uniform velocity to the top of the frame and slowly adjust the height of the frame. Put the gasket and rubber pad assembly on the position as shown in Figure 6-2-13 and let the cab steadily fall on the cab mounting base. Align holes and join them with pins.

94

Chapter 6 Main parts Section 2 Gearbox

Figure 6-2-13 d. Spare parts used for installation of the cab S/N.

Name of material

1

Cab system

Material code

Quantity of material

Remark

1 30812900102

2

Rubber pad

3

Pin

4

Nylon self-locking nut M18×1.2 Washer Base plate

5 6

30812000118 51512091801 51331001120 51420170121

4 4 4 4 4

30812100843 Used equipment and tools 1 One 10-ton traveling crane; 2 Special lifting tools; ③ Bracket; ④ 5044 jackhammer; ⑤ 12 sleeve; ⑥ 1”, 2” adjustable wrenches; ⑦ 16” open-end wrench, 18” open-end wrench.

Safety prompt for lifting: (1) During lifting, the sling must be hung on a reasonable position to avoid overturn; (2) Lift it evenly and notice whether any person around is within the safety range.

4. Disassembly and Repair The list of tools, supplies and equipment: 95

Chapter 6 Main parts Section 2 Gearbox (1) Wrench (for dismounting the oil level check valve, etc.) (2) Impact wrench (for dismounting oil pan bolts, variable speed distribution valve mounting bolts, transmission oil pump bolts, rear end cover screws, etc.) (3) Hammer (4)Copper rod (5)Pliers (for dismounting cotter pins) (6) Socket wrench (7)Puller (8)Snap ring pliers (9)Jackscrew (for pushing out the rear end cover) (10) Slings (for lifting the second gear assembly, reverse planet carrier assembly, rear output shaft, gearbox assembly, etc.) (11)Special gripper (for dismounting the bearings on the the second gear assembly) (12)Ring spanner (for dismounting the second gear friction plate screws, reverse planet pinion shaft screws, etc.) (13)Screwdriver (for dismounting the second gear rotating bearings, dismounting framework oil seals and bearings on the intermediate output shaft) (14) Lifting bolts and iron wire (for lifting reverse gear planet carrier assembly) (15) Hex socket (for dismounting the rear output flange fastening nuts) (16) Special tool (for mounting the second gear piston jacket) (17) Gauge block (for checking the second gear piston bearing holes) (18) Front and rear output shaft jackets (not required if a new gearbox has no separate front and rear output shafts) (19) Mounting bracket for gearbox assembly (20) Lifting screw (used for lifting reverse pistons) (21)Dial indicator (for checking the perpendicularity of box end surface to the output shaft of variable speed pump) (22) Scraper (for trimming the variable speed pump mounting surface on the box) I. Disassembly of gearbox (1)Disassembling of gearbox assembly A-1. Put the gearbox assembly flat on the mounting jig. Use the wrench to take down 6 fastening bolts of control valve. (See Figure 6-2-14)

96

Chapter 6 Main parts Section 2 Gearbox

Figure 6-2-14 A-2. Disassemble oil pipes of all gears and lubricating pipes of all shafts with the wrench and pay attention to worn thread of bolts. (See Figure 6-2-15)

Figure 6-2-15) A-3. Dismount the oil filling pipe assembly with the wrench and check if O-ring is in good condition. (See Figure 6-2-16)

97

Chapter 6 Main parts Section 2 Gearbox

Figure 6-2-16 A-4. Unscrew 4 bolts with the wrench and take down the brake. (See Figure 6-2-17)

Figure 6-2-17 A-5. Use pneumatic wrench to dismount nylon nut M33×1.5 of the front output flange, and remove clamp plate, O-ring, washer and front output flange assembly in order. (See Figure 6-2-18)

Figure 6-2-18 A-6. Use the wrench to unscrew bolt M10. Use four (4) M10 bolts and screw them into screwed holes in box cover to take down the box cover assembly. (See Figure 6-2-19)

98

Chapter 6 Main parts Section 2 Gearbox

Figure 6-2-19 A-7. Remove bearing 6312 with a pulling tool and then take out adjusting washer, output driven gear and shaft sleeve. (See Figure 6-2-20)

Figure 6-2-20 A-8. Use pneumatic wrench to take out nut M24×1.5 and then take out gasket, rubber pad and input flange (See Figure 6-2-21)

Figure 6-2-21 A-9. Use pneumatic wrench to take out nut M33×1.5 and then take out clamp plate and rear output flange. (See Figure 6-2-22)

99

Chapter 6 Main parts Section 2 Gearbox

Figure 6-2-22 A-10. Take down the gear III clutch assembly before dismounting the gear I clutch assembly and the gear II clutch assembly; (Alternatively, take down two-shaft NF308 bearing and conduct step-by-step dismounting) (See Figure 6-2-23)

Figure 6-2-23 A-11. Take down output shaft by striking it with copper bar and try to protect output shaft from damage due to falling off. (See Figure 6-2-24)

Figure 6-2-24 A-12. Use the wrench to unscrew all clamp plates, end covers and flange bolts. (See Figure 6-2-25)

100

Chapter 6 Main parts Section 2 Gearbox

Figure 6-2-25 A-13. Take out filter screen assembly, front bearing cover assembly, end cover, oil seal cover assembly, etc. (See Figure 6-2-26)

Figure 6-2-26 A-14. Turn on return oil control valve with the jig. (See Figure 6-2-27)

Figure 6-2-27 (2) Disassembling of gear I clutch assembly B-1. Remove two seal rings and check if they are worn or damaged. (See Figure 6-2-28)

101

Chapter 6 Main parts Section 2 Gearbox

Figure 6-2-28 B-2. Use the pulling tool to take out bearing NF308, and take down adjusting washer and shaft sleeve separately. (See Figure 6-2-29)

Figure 6-2-29 B-3. Use the puller to take down the reverse gear I assembly, and then use jig to remove 2 bearings 6209, and use circlip pliers to take out 2 retaining rings 85 and one shaft sleeve. (See Figure 6-2-30 and Figure 6-2-31)

Figure 6-2-30

102

Chapter 6 Main parts Section 2 Gearbox

Figure 6-2-31 B-4. Use circlip pliers to take out retaining ring150 and take down clutch piston clamp plate, driving clutch disc and driven clutch disc separately. (See Figure 6-2-32)

Figure 6-2-32 B-5. Use circlip pliers to take out retaining ring 52, take out clamp plate, spring and piston assembly, and check if seal ring has such damage as 切边, wear and tear. (See Figure 6-2-33)

Figure 6-2-33 B-6. Disassemble the other side in the steps stated in A-5. (See Figure 6-2-34)

103

Chapter 6 Main parts Section 2 Gearbox

Figure 6-2-34 (3) Disassembling of gear II clutch assembly The disassembling steps are similar to those of gear I clutch assembly. (4) Disassembling of gear III clutch assembly The disassembling steps are similar to those of gear I clutch assembly. II. Repair of gearbox (1) Repair of gear I clutch assembly C-1. Fit together the piston assembly by putting in steel ball 5 and then knocking in oil duct spacer ring with copper bar. (See Figure 6-2-35)

Figure 6-2-35 C-2. Check and make sure external seal ring (new) and internal seal ring are in good condition and have no quality defects as cut edge, wear and tear. During fitting, pay attention to the facing direction of the lip of internal seal ring. (See Figure 6-2-36)

Figure 6-2-36 C-3. Mount piston assembly, spring and clamp plate in order, and then use circlip pliers to mount retaining ring52. (See Figure 6-2-37)

104

Chapter 6 Main parts Section 2 Gearbox

Figure 6-2-37 C-4. Mount 6 driven clutch discs and 6 driving clutch disc and clutch piston clamp plate in order, and then use circlip pliers to mount retaining ring150. (Note: Depending on actual condition of friction disc, determine if new friction discs are used) (See Figure 6-2-38)

Figure 6-2-38 C-5. Use the jig to knock in bearing 6209, mount 2 retaining rings 85 into circlip groove of reverse gear I, and then mount shaft sleeve and bearing 6209 separately. (See Figure 6-2-39)

Figure 6-2-39 C-6. Mount shaft sleeve and bearing NF308 (Thermal assembling at a temperature of100℃ is recommended for bearing). (See Figure 6-2-40)

105

Chapter 6 Main parts Section 2 Gearbox

Figure 6-2-40 C-8. Mount the following components in order according to fitting method as stated in A-6: piston assembly, spring, clamp plate, retaining ring 52, driven clutch disc (6 pcs), driving clutch disc (6 pcs), clutch piston clamp plate, retaining ring 150, bearing 6209 (2 pcs), retaining ring85 (2 pcs), shaft sleeve, forward gear I and bearing NF308. (See Figure 6-2-41)

Figure 6-2-41 (2) Repair of gear II clutch assembly D-1. Mount piston assembly and prevent cut edge of internal and external seal rings. Mount spring and use circlip pliers to put retaining ring 52 in place. (See Figure 6-2-42)

Figure 6-2-42 D-2. Mount 6 driven clutch discs and 6 driving clutch discs, clamp plate and retaining ring150 in order. (Note: Depending on actual condition of friction disc, determine if new friction discs are used) (See Figure 6-2-43)

106

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Figure 6-2-43 D-3. Use the jig to mount bearing 6209. (See Figure 6-2-44)

Figure 6-2-44 D-4. Then mount shaft sleeve, retaining ring 85 (2 pcs); drive home No.2 axle shaft gear assembly slowly with copper bar. (See Figure 6-2-45)

Figure 6-2-45 D-5. Drive home bearing 6209 slowly with the jig. (See Figure 6-2-46)

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Figure 6-2-46 D-6. Mount shaft sleeve and No.2 axle forward gear. (See Figure 6-2-47)

Figure 6-2-47 D-7. Mount gasket and bearing NF308 (bearing adopts thermal assembling at temperatures 90~100℃). (See Figure 6-2-48)

Figure 6-2-48 D-8. Fit the other side by repeating the methods as stated in D-1 ~ D-3; D-9. Use the jig to mount bearing 6209 and shaft sleeve, fit retaining ring 85 onto No.2 axle first gear, and then drive home No.2 axle first gear assembly slowly with copper bars. (See Figure 6-2-49)

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Figure 6-2-49 D-10. Drive home bearing 6209 with the jig. (See Figure 6-2-50)

Figure 6-2-50 D-11 Mount shaft sleeve and No.3 axle reverse gear. (See Figure 6-2-51)

Figure 6-2-51 D-12. Mount gasket and bearing NF308 (bearing adopts thermal assembling at temperatures 90~100℃). (See Figure 6-2-52)

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Figure 6-2-52 (3) Repair of No.3 axle clutch assembly E-1. Mount the piston assembly and prevent cut edge of internal and external seal rings. Mount the spring and use circlip pliers to put retaining ring 52 in place. (See Figure 6-2-53)

Figure 6-2-53 E-2. Mount 6 driven clutch discs and 6 driving clutch discs, clamp plate and retaining ring150 in order. (See Figure 6-2-54)

Figure 6-2-54 E-3. Use the jig to mount bearing 6209 and shaft sleeve, fit retaining ring 85 onto No.3 axle second gear, and then drive home the No.3 axle second gear assembly slowly with copper bar. (See Figure 6-2-55)

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Chapter 6 Main parts Section 2 Gearbox

Figure 6-2-55 E-4. Drive home bearing 6209 with the jig. (See Figure 6-2-56)

Figure 6-2-56 E-5. Mount shaft sleeve, No.3 axle third gear, shaft sleeve and bearing NF308 (bearing adopts thermal assembling at temperatures 90~100℃). (See Figure 6-2-57)

Figure 6-2-57 E-6. Fit the other side and mount shaft sleeve, No.3 axle output gear and bearing NF309 in order (bearing adopts thermal assembling at temperatures 90~100℃). (See Figure 6-2-58)

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Chapter 6 Main parts Section 2 Gearbox

Figure 6-2-58 (4) Repair of gearbox assembly F-1. Fit together the control valve assembly and make sure fitting surface must be free of particles, foreign matters or scar. Apply force (100Nm twisting force) on bolt M12×110 with torque wrench. (See Figure 6-2-59)

Figure 6-2-59 F-2. Fit together oil seal cover assembly, end cover, rear output flange assembly (Note: Adjust the gap behind oil seal cover and end cover before fitting paper gasket and adjusting washer). Afterwards, install the rear bearing end cover and tighten bolt M12×35 using torque wrench with a 100Nm torque. (See Figure 6-2-60)

Figure 6-2-60 F-3. Use jig to mount the output shaft assembly. (See Figure 6-2-61)

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Figure 6-2-61 F-4. Remount the repaired No.1 axle clutch assembly into No.2 axle clutch assembly, and then fit the No.3 axle assembly. Afterwards, rotate all shafts to see that they engage well. (See Figure 6-2-62)

Figure 6-2-62 F-5. Mount shaft sleeve, output driven gear, shaft sleeve and bearing 6312. (See Figure 6-2-63)

Figure 6-2-63 F-6. d and kept clean, and fit together box cover assembly (including new paper gasket for box cover), spring pad 10 and bolts 10×30 (after tightening, apply a 55Nm torque on bolts with torque wrench) (Before fitting, check if outer race of bearing for check box cover assembly NF308/NF309 has any scar. Make bearing replacement if there is scar on outer race). (See Figure 6-2-64)

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Figure 6-2-64 F-7. Check and make sure seal ring is in good condition and has no quality defects as cut edge, expiration, wear and tear. Fit seal ring of each shaft. (See Figure 6-2-65)

Figure 6-2-65 F-8. Mount sealing gasket, end cover assembly of each shaft and bolts M12×35 (after tightening, apply a 100Nm torque using torque wrench). (See Figure 6-2-66)

Figure 6-2-66 F-9. Mount adjusting washer, sealing gasket (new), front bearing end cover assembly (including seal ring, check if seal ring is in good condition) in order, and tighten the bolts (after tightening, apply a 100Nm torque using torque wrench). (See Figure 6-2-67)

Figure 6-2-67 114

Chapter 6 Main parts Section 2 Gearbox F-10. Fit joints on first gear, second gear, third gear, R gear, F gear and oil inlet end covers in order; apply 567 sealant on screw thread before fitting. (See Figure 6-2-68)

Figure 6-2-68 F-11. Fit the joints. Apply 567 sealant at 2~3 threads of the joints before fitting. (See Figure 6-2-69)

Figure 6-2-69 F-12. Mount joints A8 and A10 and then use a special jig to tighten the joints. (See Figure 6-2-70)

Figure 6-2-70 F-13. Mount lubrication joint of reverse shaft. (See Figure 6-2-71)

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Figure 6-2-71 F-14. Use the wrench to mount first gear oil pipe, second gear oil pipe (with O-ring 11×1.9 mounted inside the joint), third gear oil pipe, reverse oil pipe, forward oil pipe, reverse lubricating oil pipe, No.1 axle lubricating oil pipe, No.3 axle lubricating oil pipe in order. Conduct reliable thread connection of each oil pipe and rule out oil leakage. (See Figure 6-2-72)

Figure 6-2-72 F-15. Install the upright pedestal of the brake and 4 bolts M12×35. (See Figure 6-2-73)

Figure 6-2-73 F-16. Mount front output flange assembly, brake, washer, O-ring and clamp plate in order, and tighten nuts with pneumatic wrench. (See Figure 6-2-74)

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Figure 6-2-74 F-17. Mount 4 bolts M12×35, pull up the handle on brake caliper assembly by hand to press two friction discs close to brake disc. Then tighten the 4 bolts with pneumatic wrench. (See Figure 6-2-75)

Figure 6-2-75 F-18. Mount rear output flange and gasket in order and install nylon self-locking nuts M33×1.5. Tighten the nuts with pneumatic wrench. (See Figure 6-2-76)

Figure 6-2-76 F-19. After repair of filter assembly, check if sealing gasket is in good condition. After removal of impurities including oil sludge, mount sealing gasket, filter screen assembly, sealing gasket, flange assembly and bolts in order. (See Figure 6-2-77)

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Figure 6-2-77 F-20. After repair of clearance adjustment, fit adjusting washer onto corresponding shafts and do not mix them up. (See Figure 6-2-78)

Figure 6-2-78 F-21. Mount sealing gasket, end cover and oil seal cover. (See Figure 6-2-79)

Figure 6-2-79 F-22. Tighten bolts M10×30 (after tightening, apply a 100Nm torque using the torque wrench). (See Figure 6-2-80)

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Figure 6-2-80 F-23. Mount input flange, mount rubber pad and gasket, and tighten nuts M24×1.5 with pneumatic wrench. (See Figure 6-2-81)

Figure 6-2-81 F-24. Install valve body assembly, mount spring, valve body and valve cap, and then fit copper backing 27 and pipe joint. (See Figure 6-2-82)

Figure 6-2-82 F-25. Install the oil filling pipe assembly, check if screws for oil filling pipe are in good condition and if screw threads are damaged, and tighten screws with pneumatic wrench. (See Figure 6-2-83)

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(Repair is complete)

Figure 6-2-83

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Section 3

Drive Axle

Table of Contents 1 Structure and Functions ............................................................................................................... [120] 2 Dismounting and Installation ........................................................................................................ [121] 3 Disassembly and Repair .............................................................................................................. [123]

1. Structure and Functions Main drive 4

Brake 6

Differential 5

Wheel hub reducer 1

Axle case 3

Half shaft 2

Figure 6-3-1 (I) Functions of Drive Axle: 1. Transmission of power: After the power inputted via driving shaft of the gearbox goes through speed reduction and torque multiplication, the driving direction is changed (via driving and driven gear) Through semiaxle driving the rotation of left and right tires, the vehicle moves forward or backward and left and right driving wheels are able to rotate at different speeds. 2. Supporting vehicle weight: Front and rear axles support the weight of the whole vehicle via frame. 3. Turning: It performs the turning of the whole vehicle (except whole-axle integral turning) 4. Differential speed: It offers such functions as vehicle swerving. (II) Structure of Drive Axle: Drive axle of wheel loader includes front axle and rear axle, whose difference lies in different directions of spiral of the spiral bevel gear pair in main drive. Front and rear axles share the same structure except that the diving spiral bevel gear pair of front axle and rear axle adopts right-handed rotation and left-handed rotation respectively. The drive axle primarily comprises axle housing, main drive (including differentials), semiaxle, wheel hub reducer and brake 6. Through drive components, the power from the engine is inputted into main drive 4 for single stage reduction, and then is transmitted via semiaxle to wheel hub reducer for speed reduction before power is outputted via hubs and tires. (III) Structure and Principle of Wheel Hub Reducer:

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Flat shaft

Rim

Figure 6-3-2 The wheel hub reducer mainly comprises sun wheel, planetary wheel, planetary carrier and gear ring. The planetary transmission principle of wheel hub reducer is illustrated as the figure. The semiaxle drives the sun wheel integrated with spline to rotate at the speed of nsun in a certain direction, while the planetary wheel engaged with the sun wheel rotates in the reverse direction. Due to stationary gear ring, the planetary carrier rotates at the speed of n carrier in the direction contrary to the rotation direction of the sun wheel. Since n carrier is below nsun, speed reduction is thus achieved. (IV) Structure and Principle of Differential:

Figure 6-3-3 A differential generally comprises 4 cone planetary gears, criss-cross shaft, 2 axle shaft gears and left & right differential housings. Operating principle of the differential is as follows: When the driving wheel is running on the ground, the resisting moment of the contact between left/right wheel and the ground acting on semiaxle line is not equal. If the difference between resisting moment of the two wheels exceeds the moment required for the rotation of planetary gear to overcome internal resistance, the planetary gear will rotate around its own axis, thus causing the left semiaxle gear and the right semiaxle gear to rotate in contrary directions. As long as the difference between resisting moment of left and right wheels exceeds the moment enough to overcome the friction against internal rotation of the differential, the left and right semiaxles rotate at their different speeds, thus realizing speed reduction.

2. Dismounting and Installation Tools needed: 1. 2. 3. 4. 5. 6. 7. 8. 9.

Two 10t travelling cranes Special lifting tools Special carrier for front and rear axles Special lengthened sleeve K50 air blasting machine 46 anti-reverse wrench 46 sleeve 1”, 2” adjustable wrench 16-18 open end wrench 123

Chapter 6 Main parts Section 3 Drive Axle 10. 11. 12.

19-22 open end wrench 27-30 open end wrench 700N·m, 1200N·m torque wrench

(1) Schematic diagram for location of drive axle in the product

Front drive axle

Front transmi ssion shaft assembl y

Intermediate support assembly

Rear drive axle assembly

Middle/rear transmission shaft assembly

Tire

Rim assembly

Figure 6-3-4 ①As shown in Figure 6-3-4, drive axle consists of front and rear axles, with front axle directly fixed on front frame and rear axle connected to rear frame via swing frame; front and rear axles are installed with 4 tires; flange face of front axle is linked to front transmission shaft; front axle is provided with protection plate and steel oil pipe; flange face of rear axle is linked to rear driving shaft; rear axle is equipped with steel oil pipe. ②Mounting bolts M24×280 (8 pcs) and lock nuts M24 (8 pcs) are used for connecting front axle to front frame; bolts M24×240 (8 pcs) and lock nuts M24 (8 pcs) are used for connecting rear axle to rear frame; bolts M14×1.5×42 (4 pcs) and lock nuts M14×1.5 (4 pcs) are used for the connection between front axle and front transmission shaft and the connection between rear axle and rear transmission shaft; lock nuts M20 (48 pcs) are used for connecting front/rear axle to front/rear rims. (2) Dismounting steps ①Remove connecting bolts between front/rear axle and front/rear driving shaft to separate front/rear axle from front/rear driving shaft; ②Remove steel pipe assembly and tee joint connecting front and rear axles; ③ Remove connecting bolts M24×280 (8 pcs) and lock nuts M24 (8 pcs) between front axle and front frame; remove connecting bolts M24×240 (8 pcs) and lock nuts M24 (8 pcs) between rear axle and rear frame; use two 10t travelling cranes to lift the frame system and push out front & rear axles; ④Hoist front and rear axles onto the fixed support and remove connecting nuts between front/rear axle and front/rear tire (12 M20 nuts per tire) Loosen nuts at the position of symmetry via 2-3 operations, lift down the tires with a special lifting device and properly mark them before placing them on tire rack; (3) Debugging requirement 124

Chapter 6 Main parts Section 3 Drive Axle If necessary, debugging shall be performed by designated personnel. (4) Installation ①Installation sequence: install front and rear axles on the frame system; connect tee joints to steel pipe assembly on front and rear axles; connect flange face of front/rear axle to front/rear driving shaft; finally install front and rear tires on front and rear axles respectively; ② Ensure cleanliness during assembly; pay attention to flange direction of front and rear axles in the course of lifting front and rear axles; 3

Take mounting torque according to the requirement of torque meter.

3. Disassembly and Repair Ⅰ.Disassembly of Drive Axle (I) Disassembly of wheel-side device 1. Place the drive axle horizontally on the assembly jig; 2. Remove fastening bolts from wheel-side end cover with a wrench, insert two long bolts into the bolt holes of the end cover, and hold the long bolts to remove the wheel-side end cover (see Figure 6-3-5);

Figure 6-3-5 3. Strike the end of the semiaxle with copper bar to eject the semiaxle (see Figure 6-3-6);

Figure 6-3-6 3.

Remove semiaxle circlip and the sun wheel (see Figure 6-3-7);

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Figure 6-3-7 5. Draw out the semiaxle carefully by hand (see Figure 6-3-8);

Figure 6-3-8 6. Take down the cushion from outer end face of planetary carrier and check if the cushion is damaged (see Figure 6-3-9);

Figure 6-3-9 7. Screw out bolts on the perimeter of planetary carrier; (NOTE: bolts screwed out shall be properly kept by fitting them with corresponding nuts, washers and elastic cushions) (see Figure 6-3-10);

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Figure 6-3-10 8. Let an iron bar go through bolt holes at both ends of the junction surface of planetary carrier, pry the planetary carrier gently to separate the junction plane (see Figure 6-3-11) Then turn the bolt holes with the iron bar inside to face downward, hook on the two bolt holes in planetary carrier with two hooks of the lifting device, pull out the iron rod, and remove and dismount the planetary carrier;

Figure 6-3-11 9. Use a slotted screwdriver to pry up the thrust washer (see Figure 6-3-12), strike gently in the loosening direction of circular nut with a hammer and chisel (or thin iron bar) to loosen the nut (see Figure 6-3-13), and then screw off the circular nut by hand;

Figure 6-3-12

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Figure 6-3-13 10. Remove the annular gear (see Figure 6-3-14)

Figure 6-3-14 11. Twist off fixing bolts of brake caliper with a wrench and then remove the brake caliper (see Figure 6-3-15);

Figure 6-3-15 12. Take down bearing inner race (see Figure 6-3-16);

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Figure 6-3-16 13. Hook on the bolthole of hub assembly with the lifting device to cause the assembly to move outward a little. Then fix the hub with iron chain and dismount the hub assembly (see Figure 6-3-17);

Figure 6-3-17 14. Take down oil baffle plate, oil seal seat, wheelside oil seal and dust guard from the support shaft (see Figure 6-3-18);

(II) Disassembly of Main drive

Figure 6-3-18

15. Take down main drive bolts with the wrench and lift out the main drive with the lifting device (see Figure 6-3-19);

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Figure 6-3-19 II. Repair of Drive Axle NOTE: Before mounting, all parts shall be cleaned; any worn or damaged parts shall be replaced with new ones. (I) Repair of rim components A-1. Use the oil press to press outer race of bearing32024 and outer race of bearing sleeve 32024 into the rim (see Figure 6-3-20);

Figure 6-3-20 A-2. Press oil baffle and 2 seal rings (FB150×180×15) in order (or knock into with a jig) into the rim. After pressing oil seal in, apply certain grease to avoid dry friction (see Figure 6-3-21)

Figure 6-3-21 A-3. Mount brake disc on the rim using sixteen (16) M18×2 bolts for brake disc. Elastic gasket must be provided (see Figure 6-3-22). 130

Chapter 6 Main parts Section 3 Drive Axle

Figure 6-3-22 (II) Repair of planetary carrier assembly B-1. Divide 42 roller pins into two groups, which are separated by spacers. planetary wheel, lubricate roller pins with grease. (See Figure 6-3-23)

During the mounting of

Figure 6-3-23 B-2. Put three fitted planetary wheel assemblies inside the planetary carrier, and align axle holes of planetary wheels; (See Figure 6-3-30)

Figure 6-3-30 B-3. Divide 6 planetary wheel washers into three groups, with one such washer laid on and under each planetary wheel assembly. (See Figure 6-3-31)

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Figure 6-3-31 B-4. Strike 3 planetary wheel axles lightly into planetary wheel axle hole with iron bar until axle end step is level with the surface of planetary carrier; (See Figure 6-3-32)

1. Axle end step shall be level with the end face of planetary carrier; 2. Gaps on the steps of 3 planetary wheel axles face outward to avoid interference with limit step of wheel-side end cover.

Figure 6-3-32 (III) Repair of planetary wheel and planetary carrier assembly C-1. Use oil press to fit the single row cylindrical roller bearing on driving spiral bevel gear, and make sure that the bearing is pressed close to the end face of driving spiral bevel gear. (See Figure 6-3-33)

132

Chapter 6 Main parts Section 3 Drive Axle Figure 6-3-33 C-2. Use the jig to fit outer race of 30310 bearing and outer race of 30311bearing via oil press into bearing seat. (See Figure 6-3-34) Bearing 30310 Bearing 30311 Bearing 30310

Bearing 30311

Figure 6-3-34 C-3. Use the jig and oil press to fit bearing seat on driving spiral bevel gear. (See Figure 6-3-35)

Figure 6-3-35 C-4. Use oil press to press two FB65×90×10 oil seals into gland bonnet. Flatten oil seal and then apply grease to avoid dry friction of oil seal at an early stage; (See Figure 6-3-36)

Figure 6-3-36 C-5. Fit together sealing paper gasket, gland bonnet (with oil seal flattened) and mount them on bearing seat. Make sure bearing oil sump is aligned with oil sump of sealing paper gasket; (See Figure 6-3-37)

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Figure 6-3-37 C-6. Fit the already welded flange assembly via spline engagement on driving spiral bevel gear; (See Figure 6-3-38)

See Figure 6-3-38 C-7. Mount gasket and tighten M30×1.5 nylon self-locking nut. With a torque of self-locking nut is 500-600N.m. Before gasket mounting, 598 sealant is applied; (See Figure 6-3-39)

Figure 6-3-39 (IV) Repair of differential gear assembly D-1. Purge the right shell of differential gear and put in semi-axle gear washer, semi-axle gear. Manually rotate semi-axle gear and check if there is any jamming during the fitting between semi-axle gear and right shell. (See Figure 6-3-40)

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Figure 6-3-40 D-2. Purge the left shell of differential gear and put in semi-axle gear washer, semi-axle gear. Manually rotate semi-axle gear and check if there is any jamming during the fitting between semi-axle gear and left shell. (See Figure 6-3-41)

Figure 6-3-41 D-3. Check and put the cleaned crisscross shaft on semi-axle gear, and mount bevel gear and bevel gear washer in order on the vertical shaft. After overturn, mount bevel gear and bevel gear washer in order on other 3 shafts. (See Figure 6-3-42)

Figure 6-3-42 D-4. Put the crisscross shaft assembly on crisscross hole of the right shell of differential gear, and strike lightly the center of crisscross shaft with soft iron bar to make sure crisscross shaft integrates closely into crisscross hole of the right shell of differential gear. (See Figure 6-3-43)

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Chapter 6 Main parts Section 3 Drive Axle

Figure 6-3-43 D-5. Integrate the left and right shells of differential gear through alignment. Strike the ribbed plate of left shell lightly with soft iron bar to ensure close integration of left and right shells. (See Figure 6-3-44)

Figure 6-3-44 D-6. Use eight (8) M14×139×1.5 flange bolts to connect left and right shells, and use eight (8) M14×1.5-10 nuts for tightening. Twisting torque of bolts is 200~230N.m. (See Figure 6-3-45)

Figure 6-3-45 D-7. After force application, use eight (8) 3.2×26 cotter pins for loosening prevention. Two heated bearings 30215 (heating temperature: 90°C~100°C) are mounted at bearing position of the left and right shell of differential gear. Do remember not to strike the bearings directly with iron bar. Instead, use the jig to jack up the inner race of bearing and strike lightly for fitting. (See Figure 6-3-46) 136

Chapter 6 Main parts Section 3 Drive Axle

Figure 6-3-46 D-8. Install the driven spiral bevel gear and make sure the fitting surface is clean. After mounting 12-M14×1.5×52 bolts, put the gear on the jig. Screw in 12-M14×1.5 slotted nuts and pretighten them with 80% torque before applying a 200~230N.m torque with torque wrench (see Figure 6-3-47). Finally use twelve (12) 3×25 cotter pins to prevent loosening. (See Figure 6-3-48)

Figure 6-3-47

Figure 6-3-48 (V) Repair of main reducing gear assembly E-1. The fitting surface between carrier assembly and bearing seat is applied with 598 surface sealant. After one round of 598 surface sealant applied, it shall be applied once along the circle of each oil groove. The inner wall of bearing seat used together with the carrier shall be also applied with 598 surface sealant, and 598 surface sealant shall be also applied once around the circle of each oil groove. The fitted driving gear assembly shall be fastened with seven (7) M14×1.5×50 bolts and one (1) M12×1.5×45 bolt, and such bolts must be equipped with elastic washer of corresponding specifications. Twisting torque of M14×1.5×50 is 130N.mm, while the twisting torque of M12×1.5×45 is 120N.m. (See Figure 6-3-49)

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Chapter 6 Main parts Section 3 Drive Axle

Figure 6-3-49 E-2. Turn over the carrier and put the differential gear assembly on the carrier as shown in the diagram. Screw in 2 adjusting nuts, cover them with two bearing caps, screw in four (4) M22 ×2.5×105 bolts and pretighten them with 80% torque using pneumatic wrench. The torque of M22×2.5 ×105 is 500~600N.m (See Figure 6-3-50);

Figure 6-3-50 E-3. For the purpose of backlash adjustment between driving and driven spiral bevel gears, first use red lead on tooth face of driven spiral bevel gear and observe mesh mark. Mesh mark shall be ≥40% in the tooth depth direction and ≥50% in the tooth length direction (See Figure 6-3-51). Position of contact mark on driven gear face Drive forward

Drive back

Adjustment method Make driven gear move close to driving gear. If gear clearance thus becomes too small, move the driving gear outward.

Gear movement direction

138

Chapter 6 Main parts Section 3 Drive Axle Make driven gear move away from driving gear. If gear clearance thus becomes too big, move the driving gear inward.

Make driving gear move close to driven gear. If gear clearance thus becomes too small, move the driven gear outward. Make driving gear move away from driven gear. If gear clearance thus becomes too big, move the driven gear inward.

E-4. Tighten M10 bolts tighten, fasten adjusting nuts, and wind up M10 bolts with intertwined iron wires for loosening prevention (See Figure 6-3-52).

Figure 6-3-52 E-5. Install thrust bolts, apply 598 surface sealant to thrust bolts with copper bush, lock washer and nuts already mounted, and screw those bolts into the carrier. Use the pneumatic tool to drive them to required positions (Screw in thrust bolt to contact the driven spiral bevel gear before loosening about 1/4), fasten them with nuts and tighten them with lock washers (See Figure 6-3-53).

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Chapter 6 Main parts Section 3 Drive Axle

Figure 6-3-53 (VI) Repair of drive axle assembly F-1. Mount oil baffle and oil seal seat on wheel-side support shaft through thermal assembling, and ensure uniform contact between end face of oil seal seat and dust shield; dust shield shall have uniform contact with end face of end axle φ130, and spacer shall be installed at the end of wheel-side support shaft. Such spacer shall be flattened through light strike (See Figure 6-3-54). Spacer installation and maintenance

Spacer installation & maintenance

Figure 6-3-54 F-2. Fit the already installed rim assembly onto wheel-side support shaft. While fitting the bearing, apply grease evenly along inner race of the bearing; while fitting the rim, use the special jig on wheel-side support shaft to protect oil seal (See Figure 6-3-55).

Figure 6-3-55 F-3. Mount inner ring before putting it into taper sleeve. Flatten taper sleeve with the jig. (See Figure 6-3-56)

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Chapter 6 Main parts Section 3 Drive Axle

Figure 6-3-56 F-4. Mount round nut, gasket 85and round nut in order. It is noted that gasket 85 should have two claws planted on round nuts, with one claw grasping the gap of inner round net and with the other claw grasping the gap of outer round nut (See Figure 6-3-57).

Figure 6-3-57 F-5. Fit the planetary carrier assembly. Check if the interior of planetary carrier is clean and free of foreign matters. Align rim bolt holes using an iron bar to go through rim bolt holes of planetary carrier and the rim (See Figure 6-3-58).

Figure 6-3-58 F-6. Mount 12 rim bolts, and mount twelve (12) 20 spring pads and 12-M20×1.5 nuts. Turn the wheel carrier and check if it has such problem as jamming. Screw in 12-M20 nuts by 3-4 threads and pretigthen M20nut diagonally with a 80% pretightening force using a pneumatic tool. The required torque is 370~450N.m, and make sure rim nuts are mounted on the outside. (See Figure 6-3-59) Rim Nut

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Chapter 6 Main parts Section 3 Drive Axle

Rim, nut

Figure 6-3-59 F-7. Fitting of brake caliper: put two brake discs into brake caliper with friction surface facing inward, and brake discs are supported by copper column of brake caliper (See Figure 6-3-66).

Figure 6-3-66 F-8. Tighten the fitted brake caliper using six (6) M20×65 bolts and six (6) M20 elastic gaskets, and tightening torque of bolt is 370~450N.m. Pre-tighten the bolt with 80% force using a pneumatic wrench, and then apply the required torque with a torque wrench. (See Figure 6-3-67)

Figure 6-3-67 F-9. Check if internal chamber of axle housing has any foreign matter. Use a caulking gun to apply 598 surface sealant evenly on the big flange surface of axle housing to form a closed loop without any gap. Use 2-M12×50 bolts, 9-M12×40 and 3 M12 stud bolts to fasten the fitted main reducing gear assembly on axle housing, and the torque of M12 bolt is 100N.m. After application of force on bolts, check if elastic gasket is damaged. (See Figure 6-3-68)

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Figure 6-3-68 F-10. Install semi axle with its side with circlip groove facing outward. Put in sun wheel and turn the planetary carrier to see if there is any jam during engagement between planetary wheel and sun wheel. (See Figure 6-3-69)

Figure 6-3-69 F-11. Mount elastic retaining ring 50 and plug. (See Figure 6-3-70)

Figure 6-3-70 F-12. Knock stop block into wheel-side end cover. (See Figure 6-3-71)

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Figure 6-3-71 F-13. Mount sealing gasket and wheel-side end cover and fasten them with six (6) M12×1.25×30 bolts and six (6) gaskets 12. Tightening torque of bolt is 80~100N.m (See Figure 6-3-72)

Figure 6-3-72 F-14. After installation, conduct air pressure test on axle housing with test pressure of 0.2~0.3Mpa; after charging of gear oil, conduct test run in accordance with running test program. (See Figure 6-3-73)

Figure 6-3-73

144

Chapter 6 Main parts Section 3 Drive Axle

Appendix: Tools, devices and appliances used for disassembly and repair of drive axle 1. Carrier for drive axle assembly; 2. Pneumatic wrench; 3. Iron bar (its diameter is slightly smaller than that of screw hole in the planetary carrier and its length is about 300mm); 4. Crane, hooks and iron chain; 5. Hex wrench (used for disassembling and assembling circular nuts and fixing bolts); 6. Hammer and chisel; 7. Socket wrench (used for disassembling and assembling fixing bolts of brake caliper); 8. Jig fixed on the workbench and matched with inner diameter of 32224 bearing outer race; 9. Press machine; 10. Flat and round iron bar capable of pressing 32024 bearing outer race below end face; 11. Copper bar (its diameter is some 50mm and its length is some 300mm) 12. 0# crocus cloth; 13. Weight for installation of 32215 bearing inner race; 14. Weight for installation of 31310 bearing outer race; 15. Weight for installation of NUR2306E bearing inner race; 16. Circlip pliers; 17. Weight for installation of 31311 bearing inner race; 18. Fixing jig for driving spiral bevel gear; 19. Dial gauge; 20. Red lead; 21. Mounting jig for input flange; 22. Sealant; 23. Iron wire; 24. Socket wrench.

145

Chapter 6 Main parts Section 4 Air Brake Valve Assembly

Section 4 Air Brake Valve Assembly 1 Structure and Functions ..................................................................................................................................[144] 2 Dismounting and Installation ..........................................................................................................................[145] 3 Disassembly and Repair .................................................................................................................................[146]

1. Structure and Functions

Figure 6-4-1

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Chapter 6 Main parts Section 4 Air Brake Valve Assembly

(I) Functions It serves as the control element of service brake which enables the whole vehicle to decelerate and stop. (II) Working principle When the brake pedal is stepped on, certain pressure is exerted on balancing spring via post rod and the piston is forced to move down. As a result, the passage between air outlet and the air is closed, and the air inlet valve is pushed open. Compressed air inflates the braking element via air outlet, thus effecting the braking. When the brake pedal is released, the balancing spring pushes all valves back to original position. Air inlet is closed, and the air outlet is connected to the exhaust opening. Compressed air is discharged into the air through exhaust opening, thus releasing the braking.

2. Dismounting and Installation Tools: 1. 22-24 open end wrench; 2. 5044 air blasting machine; 3. M8 sleeve. I. Location of air brake valve assembly on the product The air brake valve is fitted in the cab by fixing it on cab chassis with four M8×25 bolts. Foot pedal is on cab chassis, see Figure 6-4-2; other parts are below cab chassis, see Figure 6-4-3; II. Dismounting steps ①Before dismounting, step on the foot pedal several times to make sure all pressure is released. Check and make sure the loader’s power switch is disconnected; ②Unscrew the connecting nuts of 4 flexible hoses and 2 electric wires connected to the air brake valve, and separate 4 flexible hoses and 2 electric wires from the air brake valve; ③Loosen the M8×25 bolts linking the air brake valve to cab chassis with the wrench, and take out the air brake valve; III. Installation ①Fix the air brake valve on cab chassis; join the dismounted 4 flexible hoses and 2 electric wires to corresponding joints of the foot brake valve; ②Check sealing surface and sealing elements of pipes and ensure their cleanliness during the fitting process.

147

Chapter 6 Main parts Section 4 Air Brake Valve Assembly

Figure 6-4-2

Figure 6-4-3

3. Disassembly and Repair Tools: a) Pincers; b) Open end wrench; c) Double offset ring spanner; d) Socket wrench; e) Circlip pliers. (I) Disassembling process 1.Take out cotter pins on pedal pin (see Figure 6-4-4), draw out pedal pin, and remove the pedal (see Figure 6-4-5);

148

Chapter 6 Main parts Section 4 Air Brake Valve Assembly Cotter pin

Figure 6-4-4

Pedal pin

Figure 6-4-5 2.Screw off 3 bolts on cab connecting plate (see Figure 6-4-6), and take down dust hood and cab connecting plate (see Figure 6-4-7);

Figure 6-4-6

149

Chapter 6 Main parts Section 4 Air Brake Valve Assembly

Figure 6-4-7 3. Press the piston down by hand, take out the circlip fixing the piston with circlip pliers (see Figure 6-4-8), and remove the piston and spring (see Figure 6-4-9);

Figure 6-4-8

Figure 6-4-9

150

Chapter 6 Main parts Section 4 Air Brake Valve Assembly NOTE: If piston ring and the bottom of piston rod are worn or damaged, they shall be replaced. 4. Screw out pressure switch (see Figure 6-4-10) and take out closing ring and diaphragm (see Figure 6-4-11);

Figure 6-4-10

Figure 6-4-11 5. Keep the piston hole of valve body downward (see Figure 6-4-12) One person holds down the outer cover of air return port, and the other person takes out the retainer ring out of the port using the circlip pliers. After relaxing the hands slowly, remove the outer cover and take out inner cover, spring and copper bush (see Figure 6-4-13); by this time, the disassembly of the air brake valve is completed.

Figure 6-4-12

151

Chapter 6 Main parts Section 4 Air Brake Valve Assembly

Figure 6-4-13 (II) Repair process (1)Clean all parts with special cleaning fluid before putting them on the clean assembling stand in the dust-free room (see Figure 6-4-14); replace any worn or damaged part;

Figure 6-4-14 (2)Keep the big role of valve body (i.e., piston hole) downward, put copper bush in air return hole (see Figure 6-4-15), and then put in the spring (see Figure 6-4-16), inner cover and outer cover (see Figure 6-4-17) Press against the outer cover with an iron rod or socket and install the circlip (see Figure 6-4-18);

152

Chapter 6 Main parts Section 4 Air Brake Valve Assembly

Figure 6-4-15

Figure 6-4-16 Outer cover Inner cover

Figure 6-4-17

153

Chapter 6 Main parts Section 4 Air Brake Valve Assembly

Figure 6-4-18 (3)Turn the valve body by 180 degrees, keep piston hole upward, put in the spring and piston, and then install the circlip; (see Figure 6-4-19 ~ Figure 6-4-21)

Figure 6-4-19

Figure 6-4-20

154

Chapter 6 Main parts Section 4 Air Brake Valve Assembly

Figure 6-4-21 (4) Put the diaphragm and circlip in the hole of pressure switch (see Figure 6-4-22), and then screw on the pressure switch (see Figure 6-4-23);

Figure 6-4-22

Figure 6-4-23 5. Install the cab connecting plate and 3 bolts (see Figure 6-4-24), and tighten up with the wrench;

155

Chapter 6 Main parts Section 4 Air Brake Valve Assembly

Figure 6-4-24 6. Mount the dust hood (see Figure 6-4-25);

Figure 6-4-25 7. Put the pedal in place and install the pedal pin (see Figure 6-4-26) Then push cotter pins through the hole at the end of pedal pin and use the pincers to split cotter pins at the ends (see Figure 6-4-27) to prevent pedal pin from slipping out; by this time, the repair of the air brake valve is complete.

Figure 6-4-26

156

Chapter 6 Main parts Section 4 Air Brake Valve Assembly

Figure 6-4-27

157

Chapter 6 Main parts Section 4 Air Brake Valve Assembly

158

Chapter 6 Main parts Section 5 Combination valve of oil-water separator (Model SH380D)

Section 5 Combination valve of oil-water separator (Model SH380D) Table of Contents 1 Structure and Functions....................................................................................................................................[155] 2 Dismounting and Installation............................................................................................................................[156] Automatically adjust the working pressure of the pneumatic brake system, and automatically discharge the filtered-out oil, water and dust via load-removal.

1. Structure and function (I) Functions 1. Separate the oil and water inside the compressed air and automatically discharge the separated oil and water. 2. Control the pressure of the air circuit system within the scope of rated pressure. 3. Safety protection of system pressure. Automatically release pressure when the system pressure exceeds the pressure limit. (II) Structure

1. Adjusting screw 2. Pressure adjusting spring 3. Upper regulating valve 4. Control piston 5. Lower regulating valve 6. Oil and water release valve 7. Oil collector 159

Chapter 6 Main parts Section 5 Combination valve of oil-water separator (Model SH380D) 8. Air bleed piston 9. Filter cartridge 10. One-way valve 11. Orifice plug 12. Safety valve 13. Wing nut (III) Working principle Adjustment and control of system pressure: The valve takes effect when the pressure inside the pressure control chamber (Chamber A) changes. The air pressure inside Chamber A is linked to the system via orifice plug 11. When the inflation pressure of the system gradually increases and approaches the adjusting pressure value of 784±20kPa, the air pressure inside Chamber A is enough to overcome the counterforce of the spring and pushes the diaphragm to drive Piston 4 to move upward and drive Upper Regulating Valve 3 to close and Lower Regulating Valve 5 to open. When the Lower Regulating Valve 5 opens, Chamber B is linked to Chamber A. At such time, the compressed air entering Chamber B pushes the Air Bleed Piston 8 to move downward to open Oil and Water Release Valve 6, so that the oil and water inside chamber C and the air inside the oil-water separation chamber are released, and air supply to the system is stopped until the air pressure inside Chamber A and Chamber B drops and Control Piston 4 and Air Lease Piston 8 return to their original positions. The resume of air supply starts when the system air pressure is lower than the adjusting pressure of 50-100kPa, i.e. when air consumption of the system causes the system air pressure to drop to 700-750kPa, the counterforce of the spring of Control Piston 4 and Air Release Piston 8 is enough to drive them back to their original positions and start the new circulation. After screwing off Wing Nut 13, you may use the air and puncture tire with the air from the system.

2. Dismounting and installation I. Introduction of the position of combination valve of oil-water separator (hereinafter referred to as the Valve) on the product ① The Valve is installed at the lower right position of the engine and connected with the engine via the holder on the Valve, and two steel wire hoses are connected with the two joints on the Valve; ② Install two bolts (M8×25), spring washer and flat washer; II. Steps of dismounting 1

Before dismounting, step on the brake pedal for several times to ensure that the pressure inside the braking system has been completely released;

2

Loosen the nuts that connect the two steel wire hoses, and the separate the steel wire hoses from the Valve;

3

Use a wrench to loosen the blot (M8×25) that connects the holder and the engine, and then separate the Valve, the holder assembly and the engine;

4

Use a wrench to loosen the bolt (M8×85) that connects the Valve and the holder, and then separate the Valve and the holder;

III. Installation 1

Use the bolt (M8×85) to install the Valve onto the holder;

2

Use two bolts (M8×25), spring washer and flat washer to install the Valve and holder assembly onto the engine;

3

Screw on the nuts that connect the two steel wire hoses, and then install the two steel wire hoses onto the Valve.

Note: during the installation process, keep the pipe sealing surface and sealing components clean.

160

Chapter 6 Main parts Section 6 Booster Pump (Braking System)

Section 6 Booster Pump (Braking System) Table of Contents 1 Structure and Functions ..................................................................................................................................[157] 2 Testing and Adjustment .................................................................................................................................. [157] 3 Dismounting and Installation ..........................................................................................................................[158] 4 Disassembly and Repair .................................................................................................................................[159]

1. Structure and Functions (I) Functions When the brake pressure required for the vehicle is 11MPa but air pressure fails to meet this requirement, booster pump is needed for pressure boost. (II) Working principle Booster pump is air over hydraulic booster, which comprises air cylinder and hydraulic master cylinder. During operation, air inlet conducts air admission and pushes the pushrod-piston assembly to move forward. The pushrod pushes the pushrod seat assembly, while the oil filling valve blocks up the oil refilling hole in the hydraulic piston. Hydraulic pressure occurs inside the hydraulic cylinder body, and the outputted hydraulic pressure is 18×90% times the inputted air pressure. When air pressure is released, under the influence of return spring, the oil refilling hole is opened and fluid oil returns from oil refilling hole to oil cup.

2. Testing and Adjustment After installation on the vehicle, the booster pump works together with the brake caliper. Therefore, this section “testing and adjustment of booster pump” contains relevant content of brake caliper. (I) Exhaust operation of braking system ①Install the booster pump and the brake caliper entirely on the machine according to the working instruction “Dismounting and Installation”; ②First of all, the driver starts the engine, which drives the operation of inflation pump and causes the air to enter the air reservoir via pipeline 4; ③Before exhaust, open the brake caliper and air bleeder of brake caliper with 14# open end wrench; ④The driver steps on the brake pedal to transmit high pressure air in air reservoir to the first branch pipeline and the second branch pipeline respectively; ⑤High pressure air in the first and second branch pipeline pushes front booster pump and rear booster pump respectively, thus sending brake oil in oil cup into the brake caliper; ⑥The other person removes the lid of oil cup for front booster pump and rear booster pump and fills brake oil into the oil cup of booster pump; ⑦The driver steps on the brake pedal back and forth to force brake oil into front brake caliper and rear brake 3 and discharge air from the air bleeder. When brake oil bursts off in a columnar shape from the air bleeder and no air bubble appears, the air is fully discharged; ⑧Before discharge of air is completed, repeat steps ⑤ and ⑥ until the refilling of brake oil is finished and the air is discharged in 6 minutes or so. Afterwards, close the brake caliper and air bleeder of brake caliper; ⑨Finally screw up the lid of oil cup of front booster pump and rear booster pump.

161

Chapter 6 Main parts Section 6 Booster Pump (Braking System) (II) Inspection notices ①Check if there is any foreign matter in any inner chamber of each oil port; ②Before exhaust, screw off the brake caliper and its air bleeder with 14# open end wrench and close them after full discharge of air; ③The said operation involves at least two persons. (III) Dismounting tools ① 14-16 open end wrench; ②Brake oil.

Front brake caliper

Front booster pump

Pneumatic brake valve assembly

No.2 Rear No.1 branch branch booster line pump line

Rear brake caliper

Unloa Air Main line ding reservoir valve

3. Dismounting and Installation ①Fit the front booster pump on the distribution valve bracket of front frame by connecting the air pipe of foot brake valve to brake oil pipe via hollow bolt; ②Fit the rear booster pump on the bracket of rear frame (close to hydraulic reservoir) by connecting the air pipe of foot brake valve to brake oil pipe via hollow bolt; ③Install four M10×30 fixing bolts with elastic and flat washers; (1) Dismounting steps ①Dismount air pipe, brake oil pipe (hollow bolts) and fixing bolts separately; ②In case of oil leak during dismounting, oil drip pan is put in place; oil ports are protected with refilling mark; ③Dismount the rear booster pump in the engine cover (it is required to open the door of engine cover before dismounting) Remove hollow bolts and air pipe separately before removing two M10×30 fixing bolts. After dismounting, carry down the booster pump with assistance from another person; ④Dismount the front booster pump inside the front frame (Before operation, it is necessary to lift the movable arm so that the operator is able to enter the front of the front frame (NOTE: Before entry, the movable arm must be reliably supported to prevent any fall) Afterwards, open the closing plate of the front frame) Remove hollow bolts and air pipes separately before taking down two M10×30 fixing bolts. After dismounting, carry down the booster pump with assistance from another person; (2) Inspection notes ①Check if there is any foreign matter in any inner chamber of each oil port; ②Screw plugs and the pressure regulating and tightening end of booster pump may not be loosened 162

Chapter 6 Main parts Section 6 Booster Pump (Braking System) without authorization; any debugging shall be performed by designated personnel; (3) Installation ①In the course of installation, pay attention to the mounting direction of booster pump; ②Check if red light paper spacer linking hollow bolts is damaged; make replacement in case of damage; ③Conduct other operations in the sequence contrary to the dismounting sequence; ④Install the front booster pump inside the front frame (Before operation, it is necessary to lift the movable arm so that the operator is able to enter the front of the front frame (NOTE: Before entry, the movable arm must be reliably supported to prevent any fall) Afterwards, open the closing plate of the front frame) Mount two M10×30 fixing bolts before mounting air pipes and hollow bolts. ⑤Install the rear booster pump in the engine cover (it is required to open the door of engine cover before dismounting) Mount two M10×30 fixing bolts before mounting air pipes and hollow bolts; ⑥Install air pipes, brake oil pipe (hollow bolts) and fixing bolts separately; ⑦Check sealing surface and sealing elements of pipes and ensure their cleanliness during the fitting process; ⑧Take mounting torque according to the requirement of torque meter; (4) Dismounting tools ①16-18 open end wrench, 16-18 open end torque wrench; ②1”, 2” monkey wrench; 27-30 open end wrench, 350N·m torque wrench; (5) Keep dismounting record.

4. Disassembly and Repair I. Disassembling process (1)Grasp the flat position of the oil return port of booster pump with a bench clamp, use a wrench to clamp and turn the fixed plate in the loosening direction to loosen the oil outlet (see Figure 6-6-01);

Figure 6-6-01 (2)Then place the booster pump on the disassembly stand and screw off the oil outlet (see Figure 6-6-02);

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Chapter 6 Main parts Section 6 Booster Pump (Braking System)

Figure 6-6-02 (3)Screw off 6 fixing bolts of air chamber of booster pump and strike the air chamber gently with a hammer to loosen the chamber (see Figure 6-6-03) Then remove the air chamber of the booster pump (see Figure 6-6-04 and Figure 6-6-05);

Figure 6-6-03

Figure 6-6-04

164

Chapter 6 Main parts Section 6 Booster Pump (Braking System) Figure 6-6-05 (4)Take the piston out of the air chamber of booster pump, and check the integrity of the seal ring of the piston and make replacement in case of any damage (see Figure 6-6-06);

Figure 6-6-06 (5)Keep the spring clamp downward, press the cover plate down with both hands, screw off the fixing bolts of the spring and take out spring clamp and the spring (see Figure 6-6-07);

Figure 6-6-07 (6)Screw off the lid of oil cup and take out the filter screen out of the oil cup (see Figure 6-6-08);

Figure 6-6-08 (7)Take out 3 seal rings and 2 support rings from the cylinder body (see Figure 6-6-09 and Figure 6-6-10);

165

Chapter 6 Main parts Section 6 Booster Pump (Braking System)

Figure 6-6-09

Figure 6-6-10 (8)Hold the cylinder body with a bench clamp, loosen the circular nut on the lid of booster pump by striking the nut with a chisel and hammer, and then screw off the nut (see Figure 6-6-11);

Figure 6-6-11 (9) Strike the cover plate gently with a hammer and remove it (see Figure 6-6-13);

166

Chapter 6 Main parts Section 6 Booster Pump (Braking System)

Figure 6-6-13 (10)Hold the cylinder body with the bench clamp and loosen the fixing bolt of the oil cup with a socket wrench (see Figure 6-6-13) Screw off the nut and remove the oil cup (see Figure 6-6-13);

Figure 6-6-13

Figure 6-6-13 (11)Screw off the transition joint on cylinder body (see Figure 6-6-15);

167

Chapter 6 Main parts Section 6 Booster Pump (Braking System)

Figure 6-6-15 (12)Screw off the fixing bolt of the respirator and remove the dust hood (see Figure 6-6-16);

Figure 6-6-16 (13)Screw off the respirator (see Figure 6-6-15);

Figure 6-6-15 (14)Screw off the fixing bolt of the supporting rack of cover plate (see Figure 6-6-18);

168

Chapter 6 Main parts Section 6 Booster Pump (Braking System)

Figure 6-6-18 II. Repair process (1) Clean all parts with special cleaning fluid before putting them on the clean assembling stand in the dust-free room (see Figure 6-6-19); replace any worn or damaged part;

Figure 6-6-19 (2) Install 3 seal rings and 2 support rings in the cylinder body (see Figure 6-6-20);

Figure 6-6-20 (3) Mount the cover plate and ensure the alignment of locating key (see Figure 6-6-21);

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Chapter 6 Main parts Section 6 Booster Pump (Braking System)

Figure 6-6-21 (4) Screw on circular nut (see Figure 6-6-22)；

Figure 6-6-22 (5) Mount the spring and spring clamp (see Figure 6-6-23), and then turn it by 180 degrees and keep spring clamp downward. Press the cover plate down with both hands and another person puts in fixing bolt of the spring and tighten the bolt (see Figure 6-6-24);

Figure 6-6-23

170

Chapter 6 Main parts Section 6 Booster Pump (Braking System)

Figure 6-6-24 (6) Mount the piston at the bottom of air chamber of booster pump (see Figure 6-6-25);

Figure 6-6-25 (7) Join the air chamber of booster pump to the cover plate, mount 6 bolts on the perimeter of the air chamber of booster pump and tighten such bolts (see Figure 6-6-26);

Figure 6-6-26 (8) Install the respirator on the cover plate (see Figure 6-6-27) and mount the dust cover and screws (see Figure 6-6-28)

171

Chapter 6 Main parts Section 6 Booster Pump (Braking System)

Figure 6-6-27

Figure 6-6-28 (9) Mount the fixed seat on the cover plate and tighten the bolts (see Figure 6-6-29);

Figure 6-6-29 (10) Screw on the oil outlet and the oil inlet joint (see Figure 6-6-30 and Figure 6-6-31);

172

Chapter 6 Main parts Section 6 Booster Pump (Braking System) Figure 6-6-30

Figure 6-6-31 (12) Mount the oil cup and fasten it with nuts (see Figure 6-6-32);

Figure 6-6-32 (13) Mount the filter screen (see Figure 6-6-33) and screw on the lid of oil cup (see Figure 6-6-34);

Figure 6-6-33

173

Chapter 6 Main parts Section 6 Booster Pump (Braking System)

Figure 6-6-34 Attachment: List of tools and devices required for disassembly and repair of booster pump 1. Bench clamp; 2. Monkey wrench; 3. Chisel; 4. Hex wrench; 5. Hammer; 6. Screwdriver.

174

Chapter 6 Main parts Section 7 Brake Caliper

Section 7 Brake Caliper 1 Structure and Functions ..................................................................................................................................[171] 2 Testing and Adjustment .................................................................................................................................. [171] 3 Dismounting and Installation ..........................................................................................................................[171] 4 Disassembly and Repair .................................................................................................................................[171]

1. Structure and Functions Functions: As the actuating mechanism for service braking, the brake caliper clamps or releases the brake disc to apply and release the braking. Structural principles: The brake is of twin-cylinder fixing caliper type, whose calipers are fixed on axle housing and whose brake discs are fixed on wheel housing and rotate with wheels. Each wheel has one pair of calipers (with four pairs of calipers on one vehicle), and each pair of calipers has two pairs of opposed cylinder pistons. At the time of braking, high pressure oil from intensifier pump output flows into each piston cylinder via oil pipes and oil ducts of internal and external calipers, thus pushing pistons and brake pads to press close to the brake disc and force the wheels connected to the brake disc to decelerate to full stop. After release of brake, brake pads return to their original positions through the minor deflection plane of brake disc. There exists contact friction (without pressure) between brake friction linings and brake disc during vehicle operation. Heat quantity resulting from longtime driving will increase the temperature of brake fluid and even cause “air resistance”. The brake shall be periodically deflated to ensure its service performance. Brake caliper

2. Testing and Adjustment After mounting on the vehicle, the brake caliper works together with the booster pump. Therefore, the testing and adjustment of brake caliper after installation will be included in the section “testing and adjustment of booster pump”.

3. Dismounting and Installation Since the brake caliper and drive axle are installed as a whole on the vehicle, the section on the disassembly and repair of drive axle includes the instructions concerning the installation of brake caliper on drive axle. For details, refer to the section “disassembly and repair of drive axle”.

4. Disassembly and Repair 175

Chapter 6 Main parts Section 7 Brake Caliper I. Disassembling process (1) Take down brake pads from brake caliper (see Figure 6-7-01);

Figure 6-7-01 (2) Screw out 2 deflating valves and deflating seats at both ends of internal caliper (see Figure 6-7-02)

Figure 6-7-02 (3)Remove bolts and take down end cover (see Figure 6-7-03).

Figure 6-7-03 (4) Take out piston on brake caliper and dust hood circlip and dust hood on the piston in order. (See 176

Chapter 6 Main parts Section 7 Brake Caliper Figure 6-7-04 and Figure 6-7-05)

Figure 6-7-04

Figure 6-7-05 (6) Take out seal ring in piston hole of caliper body (see Figure 6-7-06);

(7) Take out fixing pins (see Figure 6-7-07).

Figure 6-7-06

177

Chapter 6 Main parts Section 7 Brake Caliper

Figure 6-7-07 II. Repair process (1)Clean all parts with specialized cleaning liquid and put them on the clean assembling stand in a dust-free room (see Figure 6-7-08); make replacement for any worn or damaged part;

(2)Mount fixing pins (see Figure 6-7-09)

Figure 6-7-08

Figure 6-7-09 (3) Install the end cover and fasten it with bolts (see Figure 6-7-10)

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Chapter 6 Main parts Section 7 Brake Caliper

Figure 6-7-10 (4) Wipe piston surface and piston hole on caliper body, and mount O-ring (see Figure 6-7-11)

Figure 6-7-11 (5) Press the piston into piston hole (see Figure 6-7-12)

Figure 6-7-12 (6) Mount the dust hood on piston (see Figure 6-7-13)

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Chapter 6 Main parts Section 7 Brake Caliper

Figure 6-7-13 (7) Mount circlips of dust hood and install other seal rings, pistons, dust hood and circlips by repeating the foregoing steps (see Figure 6-7-14)

Figure 6-7-14 (8) Mount 2 deflating valves and deflating seats at both ends of internal caliper (see Figure 6-7-15)

Figure 6-7-15 (9) Mount brake pads on brake caliper (see Figure 6-7-16) 180

Chapter 6 Main parts Section 7 Brake Caliper

Figure 6-7-16 (10) The assembly is complete (see Figure 6-7-17)

Figure 6-7-17

181

Chapter 6 Main parts Section 8 Working Pump

Section 8 Working Pump Table of Contents 1 Structure and Functions ..................................................................................................................................[178] 2 Dismounting and installation .......................................................................................................................... [178] 3 Dismounting and repair ...................................................................................................................................[179]

1. Structure and Functions (I) Functions As the power source for hydraulic system, gear pump converts mechanical energy into hydraulic energy to power the hydraulic system. (II) Working principle Working pump is joined to variable speed pump before they are fastened on the body of the gearbox. It is driven by the engine via gear pair. CBG pump is an external gear pump, which comprises an engaged pair of driving and driving gear, pump body, side plate, bearings and sealing elements. The rotation of driving gear also causes the rotation of driven gear. The place where gear teeth begin to exit from the engagement is suction chamber, while the place where gear teeth enter the engagement is pumping chamber. Suction chamber and pumping chamber are separated by the line of engagement of driven gear and by radial clearance and end clearance. With the rotation of the two gears, fluid oil is brought from suction chamber to pumping chamber, thus realizing oil suction and pumping of gear pump.

2. Dismounting and Installation (1).Position of working pump on the product

Working pump Figure 6-8-01 ①Working pump and steering pump are directly fitted at power take-off of torque converter (see Figure 6-8-01);

182

Chapter 6 Main parts Section 8 Working Pump ②Working pump is mounted on 4 double end bolts of the power take-off through 4 M12 nuts and elastic washers. Pump body is taken out only after the nuts and elastic washers are removed; Since operating space is quite limited to due to the pump located below the cab and large oil inlet and outlet pipes, the working pump is generally dismounted only after removing the entire cab from the vehicle; (2) Dismounting steps ① The cab is dismounted according to relevant requirement (see the content of the section gearbox “dismounting and installation” on cab dismounting). Interconnected lines and pipelines shall not be yanked and work safety shall be ensured during hoisting operation; ②In case of oil leak during pipeline dismounting, oil receiver and oil drums are ready for use; oil ports are protected with reassembly mark; ③Remove the oil inlet steel pipe of working pump, four M12×85 bolts and elastic washers, protect sealing elements of oil port and recycle fluid oil; ④ Remove flange gland for steel oil inlet pipe of working pump, four fixing bolts M10×35 and elastic washers, protect sealing elements of oil port and recycle fluid oil; ⑤Take the working pump out of power take-off with a special tool (e.g., crowbar). Guard against personal injury resulting from the slippage of pump from oil-stained hands; (3) Inspection notes ①Check if there is any foreign matter in inner chamber of each oil port; if splines and sealing gaskets are intact; ②Fastening end on pump body (e.g., bolts) cannot be loosened without authorization; any commissioning is performed by professionals only; (4) Installation ①Pay attention to direction during installation and the direction of oil inlet is on the inside; ②Check and clean the mounting surface. If sealing gaskets on pump body or at the power take-off end are damaged, replace them with sealing gaskets of the same model number or apply 515 plane sealant; ③Perform other operations in the sequence contrary to the dismounting sequence: ④Install the working pump in the power take-off with a special tool (e.g., crowbar). ⑤Install flange gland for steel oil inlet pipe of working pump, four fixing bolts M10×35 and elastic washers; ⑥Install steel oil inlet pipe of working pump, four bolts M12×85 and elastic washers; ⑦Check sealing elements in the pipeline during assembly. Replace any damaged sealing element with new one and ensure cleanliness; pay attention to reassembly marks to avoid wrong connection; ⑧Locking torque meets the requirement of torque meter; (5) Dismounting tools ①

16-18 open end wrench, 16, 18 sleeve and plate stem;

②

200N•m torque wrench; crowbar.

(6) Keep dismounting record.

3. Disassembly and Repair I. Disassembling process (1) Screw off 4 king bolts (see Figure 6-8-02) and 2 secondary bolts on rear cover (see Figure 6-8-03); Note: Secondary bolts may be screwed out after main gear shaft and pinion are taken out. 183

Chapter 6 Main parts Section 8 Working Pump

Figure 6-8-02

Figure 6-8-03 (2) Take down the front cover (see Figure 6-8-04) and take out oil seal and retainer ring;

Figure 6-8-04 (3) Take out the seal ring, 2 bearings and shaft sleeves (see Figure 6-8-05) and one 8-shaped side plate (see Figure 6-8-06);

184

Chapter 6 Main parts Section 8 Working Pump

Figure 6-8-05

Figure 6-8-06 (4) Take out main gear shaft and pinion (see Figure 6-8-07);

Figure 6-8-07 (5) Take up the pump body to detach the bottom end cover from the body (see Figure 6-8-08). Take off the seal ring;

185

Chapter 6 Main parts Section 8 Working Pump

Figure 6-8-08 (6) Take out two bearings and shaft sleeves (see Figure 6-8-09);

Figure 6-8-09 (7) Check wear and tear of bearings, 8-shaped side plate and gear face (see Figure 6-8-010 and Figure 6-8-11). Generally speaking, debris from bearing wear often leads to the wear and tear of side plate and gear face, thus causing internal leakage; make replacement in case of wear or damage.

Figure 6-8-10

186

Chapter 6 Main parts Section 8 Working Pump

Figure 6-8-11 II. Repair Process (1) Clean all parts with special cleaning fluid before putting them on the clean assembling stand in the dust-free room (see Figure 6-8-12); replace any worn or damaged part.

Figure 6-8-12 (2) Put in an 8-shaped sealing side from the bottom of pump body (i.e., end face with 6 screw holes) (Figure 6-8-13);

187

Chapter 6 Main parts Section 8 Working Pump Figure 6-8-13 (3) Put bearings on the shaft sleeves and then, press them into the side plate (see Figure 6-8-14) to keep their perimeters slightly below the end face of pump body;

Figure 6-8-14 (4) Put the seal ring in the end face of pump body (see Figure 6-8-15);

Figure 6-8-15 (5) Mount the bottom end cover on the end face of pump body, fit and tighten secondary bolts (see Figure 6-8-16) (tightening torque: 50N·m);

188

Chapter 6 Main parts Section 8 Working Pump

Figure 6-8-16 (6) Turn the pump body by 180 degrees (see Figure 6-8-17);

Figure 6-8-17 (7) Put in the main gear shaft (see Figure 6-8-18);

189

Chapter 6 Main parts Section 8 Working Pump

Figure 6-8-19 (8) Put in the pinion (see Figure 6-8-19);

Figure 6-8-19 (9) Hold the main gear shaft with hand to see if it rotates freely (see Figure 6-8-20);

190

Chapter 6 Main parts Section 8 Working Pump

Figure 6-8-20 (10) Mount another 8-shaped side plate (see Figure 6-8-21);

Figure 6-8-21

191

Chapter 6 Main parts Section 8 Working Pump (11) Install two bearings into shaft sleeves and then, press them into the side plate holes (see Figure 6-8-22);

(12) Install the seal ring (see Figure 6-8-23);

Figure 6-8-22

Figure 6-8-23

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Chapter 6 Main parts Section 8 Working Pump

Figure 6-8-24 (13) Install retainer ring and oil seal. (See Figure 6-8-25);

Figure 6-8-25 (14) Clean the mounting surface of pump body and install the upper cover plate (see Figure 6-8-26);

193

Chapter 6 Main parts Section 8 Working Pump

Figure 6-8-26 (15) Mount four king bolts and tighten them in the diagonal sequence (see Figure 6-8-27);

Figure 6-8-27

194

Chapter 6 Main parts Section 8 Working Pump (16) Turn the gear shaft by hand to see if it rotates freely (see Figure 6-8-28); If necessary, adjust the tightening torque of king bolts and secondary bolts.

Figure 6-8-28

195

Chapter 6 Main parts Section 9 Distribution Valve

Section 9 Distribution Valve Table of Contents 1 Structure and Functions ..................................................................................................................................[192] 2 Testing and adjustment ...................................................................................................................................[193] 3 Dismounting and installation .......................................................................................................................... [195] 4 Dismounting and repair ...................................................................................................................................[196]

1. Structure and Functions (I) Functions A distribution valve is the control element of the vehicle for the action of the working mechanism, including the lifting, lowering and floating of the boom and the retraction and unloading of the bucket. (II) Structural performance of main components of the hydraulic system: (1) Neutral position When the distribution valve is at the neutral position, oil from main pump directly returns to oil tank via the distribution valve. (2) Working position When the pilot valve is at the working position, hydraulic oil enters the control chamber at the end of a certain valve stem of distribution valve, thus pushing the valve stem to move leftward or rightward to the work device. Pressure oil resulting from the confluence of main pump and priority valve opens the one-way valve inside the distribution valve to enter a certain chamber of bucket cylinder or boom cylinder, and pressure oil in another chamber of the oil cylinder returns to the oil tank through another oil port of the selector valve. Pilot oil in another control chamber at the end of the valve stem returns to the oil tank via the pilot valve. (3) Floating position At this time, the position of valve stem of the boom is the same as during the lowering. However, because the control lever of the pilot valve is at the floating position, the sequence valve inside the pilot valve is opened and the oil from drainage duct in the selector valve flows to the oil tank through drainage port in the pilot valve. The hydraulic one-way valve between small chamber and big chamber of boom cylinder in the selector is opened, and four ports P, A2, B2 and T are interconnected. The piston rod of boom cylinder floats freely under the influence of applied force. (4) Function of overload valve and oil recharging valve When the bucket meets with impact load or interferes with other structure, the overload valve is opened for the purpose of safety protection. The oil recharging valve provides oil replenishment to prevent air suction of a certain chamber of oil cylinder.

Figure 6-9-1

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Chapter 6 Main parts Section 9 Distribution Valve

Figure 6-9-2

2. Testing and Adjustment Note: Since the distribution valve is debugged by the manufacturer before shipment, adjustment by the distributor or maintenance station is generally disallowed to ensure reliability. This section deals with the replacement and adjustment of overload valve inside the distribution valve in special cases. Before such replacement or adjustment, the distributor or maintenance station must obtain prior written consent from Lonking and the part manufacturer, and subsequent safety and quality responsibility shall be undertaken by personnel implementing such replacement and adjustment. (I) Tools required: M8 Hex wrench, wrench; (II) Location of distribution valve and overload valve on the product

Main safety valve

Distribution valve

Overload valve

Overload valve

(III) Exploded view of distribution valve

Figure 6-9-3

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Chapter 6 Main parts Section 9 Distribution Valve

Figure 6-9-4 1. Allen screw M10×45 2. O ring 50×3.1(×2) 3. Valve body 4. Safety valve 5. Screw plug (×3) 6. Bucket valve stem 7. Boom valve stem 8. Rear end cover (×2) 9. One-way valve (×3) 10. Oil recharging valve 11. Overload valve (high pressure) 12. Overload valve (low pressure) 13. Front end cover (×2) (IV) Notes on replacement and adjustment of overload valve (See Figure 6-9-4) 1. Two circumstances requiring replacement of overload valve: a. Reduced performance in bucket curl-out during bucket retraction and boom lifting under load; b. Slow boom lifting. 2. Adjustment process ①Start the loader and lift the boom cylinder and bucket cylinder to the highest point. Then flame out the engine lower the boom and bucket in the no-load mode. After they are lowered to the horizontal position, shake the control handle to realize full pressure relief of the pipeline. Get ready the oil drip pan to collect leaking hydraulic oil in the course of dismounting the overload valve; ② Break the aluminum seal, remove plastic protective casing at the top of overload valve to find the pressure regulating Allen screw inside the overload valve, and make adjustment using the Hex wrench. Tighten the screw to increase the pipeline’s unloading pressure, and loosen it to decrease the pipeline’s unloading pressure (Note: The pressure regulating bolt is set as per standard pressure before shipment, and it cannot be adjusted arbitrarily. Excessively tight adjustment will result in too high pipeline pressure and even pipe burst, while excessively loose adjustment will result in excessive internal leakage and weak boom lifting. Recommended adjustment is ±0.5 circle); 198

Chapter 6 Main parts Section 9 Distribution Valve ③ If the adjustable bolt proves ineffective in pressure regulation, it is necessary to screw off the valve body and replace the entire overload valve. (V) Inspection notes ①Check if there is any foreign matter in any inner chamber of each oil port; ②Adjusting the pressure regulating bolt is not recommended. It is advisable to replace the entire overload valve.

3. Dismounting and Installation (1) Location of distribution valve on the product

Figure 6-9-5 ①Distribution valve is fitted in the center of the interior of front frame, as shown in the figure; ② Three bolts M12×180 together with flat washers and elastic washers are fitted on valve body and front frame; (2) Preparations before dismounting ① Dismounting method: Select a dedicated maintenance site where maintenance personnel can work underneath the vehicle conveniently; ② Shut down the vehicle, set level the bucket and remove pipe joints connected to the selector valve; make reassembly marks for similar pipes; ③ Given oil leak during dismounting, oil drip pan and oil drum are ready for use; exposed oil ports are protected. (3) Dismounting steps ①Remove pilot control group-5 pipeline and make reassembly marks; ②Remove in turn 4 fixing bolts M12×35 and elastic washers for steel oil return pipe clamp of the valve, 4 fixing bolts M12×45 and elastic washers for steel oil inlet pipe clamp of the valve, 8 fixing bolts M12×42 and elastic washers for steel oil inlet & outlet pipe clamp of tilt cylinder, and 8 fixing bolts M12×42 and elastic washers for steel oil inlet & outlet pipe clamp of boom cylinder; make reassembly marks; ③After arranging all pipelines, remove 3 mounting bolts M12×180 and flat washers & elastic washers for valve body. ④ Lift the valve body out of the front frame using >100kg lifting rope and crane. If the valve body is manually carried, guard against any personal injury resulting from the slippage of the valve body from oil-stained hands. (4) Inspection notes ①Check if there is any foreign matter in inner chamber of each oil port; 199

Chapter 6 Main parts Section 9 Distribution Valve ②Screw plugs and the pressure regulating and tightening end of valve body may not be loosened without authorization; any commissioning shall be performed by professionals; (5) Installation ①Pay attention to directions during installation; ②Conduct other operations in the sequence contrary to the dismounting sequence; ③Lift the valve body to the mounting position on the front frame using >100kg lifting rope and crane; ④Install 3 mounting bolts M12×180 and flat washers & elastic washers on valve body. ⑤After arranging all pipelines, install in turn 8 fixing bolts M12×42 and elastic washers for steel oil inlet & outlet pipe clamp of boom cylinder, 8 fixing bolts M12×42 and elastic washers for steel oil inlet & outlet pipe clamp of tilt cylinder, 4 fixing bolts M12×45 and elastic washers for steel oil inlet pipe clamp of the valve, and 4 fixing bolts M12×35 and elastic washers for steel oil return pipe clamp of the valve; ⑥Install pilot control group-5 pipeline; ⑦During assembly, check sealing elements in the pipelines, make replacement in case of damage and ensure cleanliness; conduct assembly according to reassembly marks and avoid wrong pipeline connection; ⑧Locking torque meets the requirement of torque meter; (6) Dismounting tools ①16-18, open end trench, 19, 21 socket and crowbar; ②200N·m torque wrench; (7) Keep dismounting record.

4. Disassembly and Repair I. Disassembling process (1) Place the selector valve on the teardown stand (see Figure 6-9-6)

Figure 6-9-6 (2) Remove the sequence valve by loosening it with the wrench (see Figure 6-9-7);

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Chapter 6 Main parts Section 9 Distribution Valve

Figure 6-9-7 (3) Screw off the bolts on end cover of bucket valve core (see Figure 6-9-8) and remove the end cover (see Figure 6-9-9);

Figure 6-9-8

Figure 6-9-9 (4) Draw out bucket valve core, screw off fixing bolts on front cover of bucket valve core hole in the valve body, and remove spring seat, washer, spring, screw rod and valve rod (see Figure 6-9-10);

Figure 6-9-10 (5) Screw off fixing bolts on end cover of boom valve core (see Figure 6-9-11) and take out the end cover 201

Chapter 6 Main parts Section 9 Distribution Valve (see Figure 6-9-12);

Figure 6-9-11

Figure 6-9-12 (6) Draw the boom valve core out of the valve body (see Figure 6-9-13); NOTE: Because the boom valve core controls more gears, its rear end has one more spring and two more steel balls than the bucket valve core. Draw out the boom valve core with a little more force.

Figure 6-9-13 (7) Screw off fixing bolts on front cover of boom valve core hole and remove spring seat, washer, spring, screw rod and valve rod (see Figure 6-9-14);

202

Chapter 6 Main parts Section 9 Distribution Valve

Figure 6-9-14 (8) Take off the main safety valve (see Figure 6-9-15);

Figure 6-9-15 (9) Take off two overload and oil recharging valves (see Figure 6-9-16);

Figure 6-9-16 (10) Take off four screws on rear cover (see Figure 6-9-17) and remove the rear cover and seal ring (see Figure 6-9-18);

203

Chapter 6 Main parts Section 9 Distribution Valve

Figure 6-9-17

Figure 6-9-18 (11) Screw off three pressure measuring end caps (see Figure 6-9-19);

Figure 6-9-19 (12) Take off three one-way valve assemblies (see Figure 6-9-20); break down each one-way valve (see Figure 6-9-21). The disassembly is completed (see Figure 6-9-22).

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Chapter 6 Main parts Section 9 Distribution Valve

Figure 6-9-20

Figure 6-9-21

Figure 6-9-22 II. Repair process (1) Clean all parts with special cleaning fluid before putting them on the clean assembling stand in the dust-free room (see Figure 6-9-23); replace any worn or damaged part;

205

Chapter 6 Main parts Section 9 Distribution Valve

Figure 6-9-23 (2) Assemble one-way valves (see Figure 6-9-24) and install them on the valve body (see Figure 6-9-25);

Figure 6-9-24

Figure 6-9-25 (3) Mount three pressure measuring end caps (see Figure 6-9-26);

Figure 6-9-26 (4) Install the rear cover and fit the screws (see Figure 6-9-27);

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Chapter 6 Main parts Section 9 Distribution Valve

Figure 6-9-27 (5) Install two overload and oil recharging valves (see Figure 6-9-28);

Figure 6-9-28 (6) Install the main safety valve (see Figure 6-9-29);

Figure 6-9-29 (7) Assemble the boom valve core and insert it into the valve body (see Figure 6-9-30); mount the front end cover of the boom valve core and tighten the fixing bolts (see Figure 6-9-31);

207

Chapter 6 Main parts Section 9 Distribution Valve

Figure 6-9-30

Figure 6-9-31 (8) Assemble the bucket valve core and insert it into the valve body (see Figure 6-9-32); mount the rear end cover of the bucket valve core and tighten the fixing bolts (see Figure 6-9-33);

Figure 6-9-32

Figure 6-9-33 (9) Install the sequence valve (see Figure 6-9-34); the repair is completed (see Figure 6-9-35).

208

Chapter 6 Main parts Section 9 Distribution Valve

Figure 6-9-34

Figure 6-9-35

209

Chapter 6 Main parts Section 10 Lift arm Cylinder

Section 10 Lift arm Cylinder

Table of Contents 1 Structure and Functions ..................................................................................................................................[206] 2 Dismounting and Installation ..........................................................................................................................[206] 3 Disassembly and Repair .................................................................................................................................[207]

1. Structure and Functions (I) Functions As an actuating element of hydraulic system, lift arm cylinder lifts and lowers the lift arm by controlling oil feed into small and big chambers of the cylinder. (II) Working principle The cylinder generally comprises cylinder barrel and piston rod, and the cylinder barrel has two oil inlets with one connected to big chamber of the cylinder (i.e., non-rod chamber) and the other connected to small chamber of the cylinder (i.e., rod end chamber) When oil is fed into big chamber of the cylinder, the piston rod is pushed out; when oil is fed into small chamber of the cylinder, the piston rod is taken back. Through the said actions, the action of the mechanical device is controlled.

2. Dismounting and Installation (1) Location of lift arm cylinder on the product

Lift arm cylinder

Figure 6-10-1

①This vehicle has two lift arm cylinders (including left and right cylinders) fitted between the lift arm and the front frame (shown in Figure 6-10-1); steel oil inlet & outlet pipes for external connection are non-interchangeable symmetrical parts; ②Each lift arm cylinder is mounted between front frame and the lift arm using two hinge pins; each hinge pin is provided with one fixing bolt M20×40 and elastic washer and flat washer; (2) Dismounting steps ① Lift and put the lift arm on a special lift arm holder horizontally or at an appropriate angle, and then release the oil pressure of the pipeline by operating the hydraulic control handle; consequently, fluid oil in the cylinder and oil pipe flows back to the oil tank; alternatively, the lift arm may be hoisted using a ≥5T crane. Shut down the vehicle. ②In case of oil leak during pipeline dismounting, oil drip pans and oil drums are ready for use; oil ports are protected with reassembly mark; ③Remove the connection between steel oil inlet & outlet pipes and rubber oil inlet & outlet hoses for the left lift arm cylinder before taking off two fixing bolts M20×40 and elastic and flat washers for hinge pins of 210

Chapter 6 Main parts Section 10 Lift arm Cylinder the cylinder linking the lift arm to the front frame. ④It is advisable to dismount the cylinder wholly before removing the steel oil inlet & outlet pipes on the cylinder (if necessary); ⑤ Avoid any bruise to oil nipple; in case of interference, remove the oil nipple before taking down the hinge pin; ⑥ Tie up the cylinder in the center using a hoisting sling with >200kg load bearing and suspend the cylinder on the crane hook. Use a special steel bar (DN: