Engine part
The starting function drives the engine to run, but there is no starting sign.
The lousy fuel system usually causes the phenomenon of causing the engine to generate. It is divided into low-pressure oil circuits and high-pressure oil circuits. It should first determine which part of the fault comes from when checking. First, the fuel injection pump bled out, the bolt loosened, and the hand oil pump was seen to see the oil condition. If it did not come out of the oil or the foam diesel oil was indicated, it would be a low-pressure oil circuit; otherwise, it would be a high-pressure oil circuit fault.
(1) Low-pressure oil circuit fault
1. There is no oil in the oil tank: treatment method: refuel
2. If the oil pipe is blocked, the treatment method: clean and dredge
3. The filter screen of the oil transfer pump is blocked. Treatment method: clean it
4. The oil pipe is aging and leaking, and it shall be replaced
5. The diesel filter is too dirty, replace it
6. The piston of the oil transfer pump is damaged and should be replaced
(2) High-pressure oil circuit fault: 1 Fuel injection pump does not work, correct 2 Fuel injector inoperative correction or replacement
（2） Premature injection time
phenomenon
1. Rhythmic and crisp “quack” metal knocking sound occurs in the cylinder
2. The engine is overheated, weak and emitting black smoke
3. Poor idle speed
4. Difficult to start
processing method
Loosen the fixing screw of the fixing plate and slowly delay the fuel injection time until the fuel injection situation improves. You can also remove the high-pressure pipe of the first cylinder and rotate the crankshaft. Pay attention to the oil level in the pressing seat of the oil outlet valve on the fuel injection pump. When the oil level fluctuates slightly, check whether the fuel injection timing scale on the flywheel coincides with the mark on the flywheel housing and whether the advanced angle meets the regulations. If it does not meet the requirements, adjust it again.
（3） Injection time too late
phenomenon
1. The cylinder has a low but unclear knocking sound
2. The engine speed cannot increase with the increase of throttle
3. Engine overheating: weak and white smoke
Check whether the fixing screw of the connecting plate is loose and displaced. Loosen the fixing screw of the fixing plate and slowly advance the fuel injection time until the fuel injection condition improves. If the adjustment is invalid, check whether the timing adjustment screw on the plunger tappet of the fuel injection pump is misaligned and readjust if it is misaligned.
（4） Engine weakness
Cause of failure
1. The oil supply of the low-pressure oil circuit is insufficient, the vent hole of the oil tank is blocked, the oil pipe is blocked, the fractured joint is loose and the gasket seal is not tight. Treatment method: find out the fault, dredge the oil circuit and replace it
2. If the air filter is blocked and the air intake is not smooth, please replace or clean the filter
3. Diesel filter is blocked, treatment method: replace
4. The oil supply of the oil transfer pump is insufficient. Treatment method: repair or replace
5. There is air or moisture in the fuel system. Treatment method: remove air or moisture
6. If the injection time is too early or too late, treatment method: adjust
7. The exhaust pipe or silencer is blocked and the exhaust is not smooth. Treatment method: clean
8. The fuel injection quantity of the fuel injection pump is insufficient. Treatment method: calibrate the oil pump
9. The atomization of individual fuel injectors is poor. Treatment method: find out where the cylinder is faulty and replace or repair the fuel injector
10. If the engine temperature is too high, handle and check the cooling system to find out the fault and eliminate it
11. The accelerator cable is not adjusted correctly, and the adjustment
12. The cylinder pressure is too low due to mechanical factors. Mechanical factors include: loose valve closing of valve distribution mechanism and serious wear of piston, piston ring and cylinder liner, adjusting valve clearance, regrinding valve or replacing piston, piston ring, lining and grinding cylinder liner.
（5） Sudden flameout during operation
phenomenon
1. Sudden flameout during engine operation
2. No abnormal symptoms before flameout
Fault cause and treatment method:
1. There is no oil in the oil tank: treatment method: refuel
2. Diesel oil is mixed with water or air. Treatment method: remove water or air
3. If the oil pipe is blocked or broken, the treatment method: dredge or replace the oil pipe
4. The fuel filter is blocked. Treatment method: replace it
5. The oil pipe joint is loose. Treatment method: squeeze the joint to drain the air in the oil circuit
6. The oil transfer pump does not supply oil. Treatment method: repair or replace the oil transfer pump
Transmission system
Hydraulic transmission
（1） Technical parameters of hydraulic transmission
1. Transmission power: 40kW
2. Input speed 1800-2400n / min
3. Steering (viewed from the input end) clockwise
4. Clutch piston stroke, 1.2-1.7mm
5. Working oil, 20# turbine oil (or 6# or 8# hydraulic transmission oil)
6. The working oil temperature is 70-95 ℃
7. The maximum oil temperature shall not exceed 110 ℃
（2） Efficiency decline
(1) Torque converter section
1. The engine speed decreases. Treatment method: increase the engine speed
2. There are bubbles in the oil. Check the tightness of the pipeline and whether the hydraulic oil has deteriorated
3. The oil temperature rise is too high or too low
(2) Transmission part
1. If the grinding inspection piece is stuck or worn, check whether the grinding inspection piece has glue, uneven contact and warpage.
2. Grind the sealing ring or O-ring, and check whether the sealing ring and groove width are worn or damaged
（3） Oil temperature too high
(1) Torque converter section
1. If the torque converter works in the low-speed ratio area for a long time, the efficiency of the torque converter is very low, or the time in the stall state is too long, change this working condition and pay attention to avoid the above working conditions.
2. In the high-speed ratio, the one-way clutch is stuck and out of control, check and eliminate it.
3. If the oil quantity is too small or bubbles are generated in the system, increase the oil quantity and adjust the pressure of the discharge valve.
4. If the oil quality is unqualified, replace it with new oil.
(2) Transmission section.
1. If the clutch is blocked, check whether the friction plate slips.
2. If the bearing is damaged, check whether the mating surface is damaged.
（4） Transmission inoperative
1. Check whether the spring of the control valve is stuck or broken
2. Check whether the central oil pressure is normal. If not, check whether the triple pump is excessively worn or damaged
3. If the central oil pressure is normal, check the clutch oil pressure. If not, check whether the sealing ring or O-ring is worn or damaged. Check the clutch and clutch piston ring for damage
4. Check whether the oil pressure of the torque converter is normal. If not, check the torque converter
Mechanical gearbox
（1） Clutch system failure
The primary manifestation of the poor technical condition of the clutch is the specific manifestation of clutch slip.
1. When the vehicle speed decreases, the vehicle speed shall not increase with the increase of engine speed
2. Difficult to start and unable to exercise
3. As the temperature of friction parts increases, the friction coefficient decreases
4. The high temperature caused by long-term slip can burn the pressure plate and scorch the clutch plate. During maintenance, adjust the pedal’s unrestricted stroke and the release lever’s height. If it cannot be released, it depends on whether the clutch shakes when combined, the incomplete separation, and the noise during combination, separation, or operation. When these phenomena occur, further check, adjust, repair, and replace relevant accessories
（2） The transmission is difficult to shift
1. Incomplete clutch separation
2. Check the joint end face of the combined sleeve and the joint gear ring for damage and deformation of the tooth gallery
3. Check whether the friction surface between the synchronous gear ring and the cone plate (gear) is worn
4. The elastic force of the positioning spring is weakened, and the coupling sleeve cannot drive the positioning pin (speed regulating key) to synchronize the gear ring. It is in close contact with the stack plate (gear) to produce a synchronous effect
5. The shift fork is bent or twisted so that the axis of the joint sleeve (clutch gear sleeve) and the common tooth are not concentric
6. The shift fork shaft is bent or rusted, and the card is stuck
All the above conditions will cause gearing or even failure to gearing. Carefully check the fault location, repair or replace relevant accessories.
（3） Transmission skip
Gear skipping is the main reason that when the load increases or the vehicle vibrates violently, the shift lever automatically jumps back to the neutral position from the gear it is engaged in.
1. If the gear and engagement teeth are worn too much, replace the gear and engagement teeth
2. If the spring of the self-locking device is too soft or broken, replace the spring
3. The wear between synchronous joint sleeve, synchronous gear ring and gear is too large. Replace relevant accessories
4. If the shift fork is bent or worn, replace or correct the shift fork
5. The steel ring of the self-locking device cannot be completely stuck in the groove of the shift fork shaft. Check whether the connecting pin and pinhole are loose and whether the control lever, shift forkball head, and socket are loose. If they are loose, they should be renewed or repaired.
Brake system
How to adjust the brake correctly
Step 1: completely loosen the handbrake handle and reduce the handbrake adjusting screw
Step 2: stop when the jacking rod of the brake master cylinder is ultimately released, and both sides must be adjusted evenly
Finally: adjust the handbrake and master cylinder ejector rod, and the unrestricted stroke of the brake pedal must be kept between 10-15mm
How to judge and eliminate unilateral brake failure
1. The barrier between the left and right wheel brake pads and the brake drum is an inconsistent adjustment
2. If some wheel brake pads are greasy or excessively worn, or the materials of two-wheel brake pads are different, repair or replace the brake pads
3. If the brake pad of one wheel is in poor contact with the brake drum or the spring force of the return spring is too different from that of the other side, repair or replace relevant accessories
4. If the air pressure of the wheels on both sides of the tightness of the wheel hub bearing is inconsistent, adjust it
Drive axle
How to judge the drive axle noise?
1. If the drive axle emits disorderly and continuous noise, the noise increases with the increase of rotating speed, which decreases or disappears during sliding. Generally, it is the noise generated after the bearing is worn. The bearing should be repaired or replaced for readjustment
2. If the driving plate emits rhythmic metal impact sound during driving, significantly when the vehicle speed changes sharply, or the sound is very obvious when starting, which is mainly caused by too large meshing clearance of crown wheel, the meshing clearance should be adjusted
3. If there is a continuous “buzzing” sound and the drive axle is heated during driving, it may be that the bearing is too tight, the backlash is too small, or the lubrication is poor. Stop the machine for inspection and add lubricating oil. If there are still the above phenomena, check and adjust the bearing tightness or gear clearance
4. If the vehicle suddenly makes a “gnawing” sound or “rattling” sound during driving, it is generally that the crown wheelset is broken or the bearing is scattered, which should be repaired immediately
Hydraulic system
1、 No lifting
1. Check whether the oil pump has enough oil output. If not, check whether the hydraulic oil in the oil tank is enough. Treatment method: add hydraulic oil, and repair the oil pump and oil inlet pipeline
2. Check the drain valve for serious internal leakage and replace it
3. Check the oil cylinder for internal leakage and damage, and replace the oil seal or oil cylinder
2、 When the oil cylinder is half lifted, it cannot be raised again
This phenomenon occurs in the following situations:
1. If there are bubbles in the hydraulic oil in the oil tank, check and replace the hydraulic oil filter element
2. There is no bubble in the hydraulic oil in the oil tank. Check and replace the oil pipe from the oil tank to the hydraulic pump
3. If the oil cylinder leaks, replace the oil seal
3、 Direction weight
1. If the oil pressure is too small, adjust the hydraulic oil flow to increase the pressure
2. If the steering cylinder leaks, replace the oil seal
3. The internal friction of the steering gear is serious or damaged. Replace the steering gear
4. If the bearing in the steering wheel system is damaged, replace the bearing
The electrical system of the internal combustion engine
1、 Characteristic of forklift circuit
1. Low voltage 2 DC 3 Single line system 4 Negative grounding 5 parallel connection
2、 Simple maintenance method of the generator without power generation:
1. Check whether the fuse is damaged and replace it
2. Check whether the electronic regulator has standard voltage input and output (490B). If there is no input voltage, check the circuit from the ignition switch to the electronic regulator. If there is no output, replace the electronic regulator
3. Check whether the carbon brush and diode of the generator are damaged and replace them
3、 The horn doesn’t sound
1. Check whether the power line from the power switch to the horn is open circuit, repair
2. Check whether the horn switch is burnt out or has poor contact, and repair it
3. Directly test whether the horn is damaged on the power supply and replace it
4、 Unable to warm up
1. Check whether the preheating relay and timer are damaged and replace them
2. Check whether the glow plug is burnt out and replace it
3. Check whether the preheating circuit is an open circuit or short circuit and repair it
5、 Troubleshooting methods for lighting system faults:
1. Check whether the bulb is damaged and replace it
2. Check whether the switch is burnt out, replace or repair it
3. Check whether the fuse and circuit are short-circuited, replace or repair

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