Common fault analysis loader maintenance knowledge of
The 1. is not able to walk one gear and can not walk, the rest of the gear is normal.
The main points of judgment:
When the loader does not walk or walk slowly, the main drive shaft rotates quickly and effectively. When the engine speed is increased, the speed of the main drive shaft is significantly increased.
The oil pressure of the gearshift and its remaining position is normal, and the pressure drops obviously after the gear is hung.
Cause of failure:
1) serious wear of bearing cover or nylon ring.
2) if the bearing cover or nylon ring is good or slightly worn, it is confirmed that the internal and external sealing ring seal of the clutch is not good.
Exclusion methods:
The replacement of damaged parts is the corresponding bearing cap or nylon ring, inside and outside the seal ring, the sleeve and the bearing cover gap adjustment.
Failure analysis: a certain position is unable to walk or walk. It can exclude the problems of various oil circuits and components such as torque converter, walking pump and pressure reducing valve. The location of the fault can only be changed after the transmission control valve to the oil path between the clutch piston. Bearing cover, nylon ring, seal ring inside and outside weak parts wear, supply to the clutch piston chamber of oil from the wear parts of a large number of leaks, resulting in low pressure. As the oil does not flow through the worn parts, the oil pressure is shown to be normal.
2. empty automatically forward, hang into the forward gear can also run normally, hang into the backstop machine stop, can not walk. The pressure of each gear is normal.
Cause of failure:
Forward clutch driven plate locking main sintering
Advance clutch piston stagnation and support one-way valve blockage
Exclusion methods:
Disengage the advance clutch, clean the oil way, replace the main and driven friction discs and related damage parts, clean the relevant parts, replace the outer sealing ring, clean the one-way valve, replace the clutch friction disc and the inner and outer sealing rings.
During the normal running of the 3. whole machine, it is not working suddenly after the two gear is hung, and the pressure of the gear and the rest of the gear is normal.
Cause of failure:
The clutch shaft broken
Exclusion methods:
Change the clutch shaft and retune the clearance of the bearing
4. the whole machine suddenly does not move forward, does not retreat, the shift work pressure is normal.
Cause of failure:
1). Failure or damage to the variable transmission valve or (40F, 50D, 50F) accumulator damage the valve stem card of the transmission valve to die or damage
2) the oil inlet blocked.
3). Accumulator oil road blockage
4). Failure of gas control cut-off valve
Exclusion methods:
Clean the transmission valve to isolate the valve stem or replace the gas control valve to dredge the relevant oil roads, repair or replace the gas control shut-off valve
5. the whole machine is working normally. Suddenly, no lifting or not walking, it is damaged or connected by an elastic joint or a connecting wheel.
Cause of failure:
Elastic coupling plate disassembly, elastic coupling plate fixed bolt damage, connecting wheel to beat tooth
Exclusion methods:
Replace the elastic joint plate and replace the connecting wheel
6. the transmission pressure is normal and the main drive shaft turns quickly and forcefully when the whole machine meets the heavy load. Cannot work normally and the digging shovel and transmission oil in a metallurgical powder
Cause of failure:
The high and low speed control rod is not at the low speed position or the transmission valve is not in place. The 1:3 clutch is damaged and the forward clutch is damaged
Exclusion methods:
Hang a high low speed rod to a low speed position and adjust the bacilli
Replacement of clutch friction plate and damage related components
The top of the 7. torque converter
Cause of failure:
The valve stem of the transmission valve is "O" and leaked, and the oil filter of the torque converter is blocked. The oil path of the torque converter or the guide wheel block is blocked, and the torque converter is blocked to the transmission oil return line.
Exclusion methods:
Replace the air control valve "O" type ring, cleaning the oil filter core or replacing the filter core, cleaning the oil roads or replacing the guide wheel seat, cleaning or replacing the tubing.
8. torque converter has abnormal sound
Cause of failure:
Torque converter connecting teeth, gear or rubber teeth damage, torque converter elastic connection plate crack, 30F, 30D torque converter main and the tooth shaft or bearing damage, main drive shaft spline incorrect or universal joint bearing clearance.
Exclusion methods:
Replace the connecting wheel or rubber tooth, replace the elastic plate, replace the main, passive gear or bearing, and adjust or adjust the gap.
9. the whole machine is working normally, the oil temperature is high, the output power is insufficient and the fluid has aluminum foam in the fluid.
Cause of failure:
The oil filter is blocked, the mechanical oil radiator is blocked, the oil return line is not smooth, the bearing damage, the torque converter three wheel wear
Exclusion methods:
Cleaning filter core or replacing filter core, replacing radiator, cleaning and dredging various oil roads or changing, replacing bearings, changing three wheels and adjusting clearance
10. low speed or high speed shift
Cause of failure:
The gap between the control part is too large or the rod is not adjusted properly, the sliding sleeve and the high and low speed gear wear, the mesh volume is too small, the clearance between the high speed gear bushing and the output shaft is too large, the fork deformation or the fork spring positioning spring break.
Exclusion methods:
Adjust the clearance of each related rod, replace the damaged sleeve and gear, change the gear bushing and adjust the gap, replace or repair the fork to replace the spring
11. the hydraulic oil in the gearbox is increased and the hydraulic oil in the working hydraulic tank is reduced.
Cause of failure:
Working pump or steering pump oil seal aging, working pump or steering pump shaft axial clearance or radial barrier oversize
Exclusion methods:
Replace the oil seal of the working pump or the steering pump, repair the check oil pump or replace the oil pump
12. the hydraulic oil in the gearbox is reduced and the hydraulic oil in the working hydraulic oil tank is increased.
Cause of failure:
Blockage of oil inlet filter net or oil pump plugging in working oil tank
Exclusion methods:
Cleaning or replacing oil filter net, replacing oil pump oil suction pipe
13. the speed change pressure is low for the whole machine after the gearbox is blocked or hung up
Cause of failure:
The transmission oil is not enough, the transmission oil sump filter is blocked, the running pump is damaged, the volume efficiency is low, the pressure of the pressure reducing valve or the inlet pressure valve is not adjusted properly, and the oil suction pipe of the walking pump is aging or dismantled seriously.
Exclusion methods:
When adding hydraulic oil to the idle speed, add the middle position of the oil shift, replace or clean the filter screen, replace the walking pump, re adjust the pressure to the required range, and replace the oil pipe.
14. loaders in normal driving, suddenly no steering, while the steering wheel can be easily rotated.
Cause of failure:
Shedding of the piston of the steering cylinder
Fracture or damage of the connecting sleeve of the steering column and the steering gear
Exclusion methods:
Replace the steering cylinder,
15. loaders in normal driving, suddenly no steering, while the steering wheel can not move.
Exclusion methods:
The roll key of the steering pump or the connecting sleeve is damaged,
Turn off for one-way valve (valve block) in the steering gear with 8MN ball (Dan Xiangfa) failure,
Replace the steering pump or the connecting sleeve, replace the valve block or the one-way valve
16. automatic steering, the steering wheel can not automatically return to the middle.
Cause of failure:
Fracture of back position spring sheet in the steering gear
Exclusion methods:
Replacement of repositioning spring or steering assembly
The 17. steering wheel offset the concave side of the ground automatically.
Damage of two-way overload buffer valve
Exclusion methods:
Replace the steering gear, clean and repair or replace the valve block
18. turn heavy
Cause of failure:
The steering pump enters the oil filter or the oil pipe is blocked, the clearance between the steering column and the steering gear is small or no clearance. The steering valve core and the valve sleeve, the stator and the rotor cooperate tightly or the overflow pressure is low or stuck, and the volume efficiency of the steering pump is low.
Exclusion methods:
Clean the filter core or replace the oil pipe, adjust its clearance, change the steering gear or wash the grinding, adjust its pressure to reach the specified value, replace the oil pump
19. turn to no end sense
Cause of failure:
The bidirectional buffer valve of the steering valve block is broken or the bidirectional buffer valve adjusts the pressure less than the steering safety valve pressure. The refueling way of the steering safety valve is blocked, and the clearance between the steering valve body, the valve sleeve and the valve core or the serious wear gap of the stator pair is too large.
Exclusion methods:
Replacing the spring or adjusting its pressure to the specified value, cleaning and dredging the line, replacing the steering gear
20.50F loader suddenly no lift in work, no turn
Cause of failure:
Lead pump rolling key or pilot pump shaft break, bearing damage at the junction of torque converter and pilot pump
Exclusion methods:
Replace the pump or # shaft key with son, bearing replacement
The 21. steering wheel turns but the steering is slow, the steering wheel turns lighter and the number of revolutions increases.
Cause of failure:
The damage of the piston seal of the steering cylinder
Bi-directional overload buffer damage
The wear gap between the rotor and the stator is too large and the efficiency of the steering pump is low
22. when the loader turns, the front bridge or the rear axle has a different sound, and the noise disappears in the straight line.
Cause of failure:
The planetary gear and the half shaft gear of the differential gear are not matched, the mesh is not good, the planetary gear of the differential gear is damaged or the surface is damaged, the adjustment of the planetary gear and the cross shaft of the differential is blocked or the gap is bad.
Exclusion methods:
Change the planetary gear or cross gear, adjust the gap or change the gear
The 23. loader drives the driving bridge with noise and does not disappear when it is skidding
Cause of failure:
The lubrication oil in the driving axle housing is insufficient, the meshing clearance of the main and driven spiral bevel gear is too small and the gap between the differential shell and the cross axle planetary gear is too large.
Exclusion methods:
Add the lubricating oil to the standard and adjust the gap to reach the specified value
24. failure phenomenon: the bridge is not driven by the sudden front axle in walking
Cause of failure:
Half axis broken
Exclusion methods:
Replacement half shaft
The 25. loader is running normally, and the four wheel produces the abnormal sound
Cause of failure:
The wheel side tapered roller bearings are damaged, the planetary roller bearings are damaged, the sun gear and planetary gear break, the internal gear ring is broken, the inner gear ring and the inner gear support rack are broken.
Method: to replace bearings, adjust the gap, replace the needle bearing, replace sun gear and planet gear, replacing the ring gear, replacing the bolt with 10 x 75
26. suddenly there is no lift, no bucket, no bucket.
Cause of failure:
The work distribution valve main safety valve is stuck.
Treatment methods:
Open the main safety valve cleaning treatment, special care not to unscrew the rear end of the safety valve pressure nut.
Fault analysis:
After the safety valve is jammed, the oil of the working pump is all flowing into the oil return line. The working pressure of the lifting cylinder and the tipping bucket cylinder can not establish the required working pressure, so that the corresponding arm and bucket are not moved. This kind of fault is usually caused by poor cleanliness of hydraulic system. For long time machine, we should check or replace hydraulic oil and oil filter element.
27. failure phenomenon:
1) the light load lifting speed is normal, over a certain weight after suddenly lifting or lifting is very slow, cold hot fault phenomenon is consistent.
2) can lift, but can not reach the maximum lift height.
Cause of failure:
1) overloading
2) the work distribution valve main safety valve adjust the pressure to turn lower.
Treatment methods:
1. eliminate overloading.
Overloading can cause early damage to the main safety valve and the work pump!
2. clean the main safety valve and re calibrate the pressure.
Note: the pressure must be in accordance with the requirements of the instructions. High pressure adjustment may cause serious damage to the work pump, the working valve and the high pressure oil pipe.
28. bucket lift crane normal, slow, and shovel material heavier, lifting speed is more slow, hot after the fault degree increased.
Cause of failure:
(1) the early wear of the piston seal of the lifting cylinder. Methods: the judge arm up to the highest position, open the inlet oil connector including a lift cylinder piston rod cavity, the assignment of the valve lever arm is in the "lifting" position, and stepped on a high speed accelerator, the leakage was observed at the interface of the lifting cylinder, a normal leakage, another judgment the lifting cylinder.
(2) the efficiency of the work pump is reduced. When the first reason is excluded, the efficiency of the pump can be reduced.
Fault analysis:
The lifting speed of the moving arm is mainly determined by the speed and efficiency of the working pump and the leakage of the lifting oil road. The damage of lift cylinder piston seal or the decrease of working pump efficiency will increase the leakage and increase with the increase of working pressure, that is, the heavier the material is, the slower the lift will be.
The 29. moving arm stops at a certain position and is unable to stop and sink.
Cause of failure:
The seals on the piston of the lifting cylinder are damaged, and the working distribution of the valve stem and the valve body
Exclusion methods:
Replace the seal on the piston and check the gap between the valve stem and the valve gap to replace the work distribution valve
30. in normal work, the working hydraulic device (lifting, turning) suddenly does not work at the same time
Cause of failure:
The work oil pump is damaged, the spline of the working oil pump and the connection sleeve keyway damage or drive the oil pump shaft broken.
Exclusion methods:
Replace the oil pump and replace the damaged parts
31. work distribution valve (lift couplet, movable arm) joystick cannot be positioned
Cause of failure:
Positioning sleeve damage, location of steel ball damage, positioning spring fracture
Exclusion methods:
Replace the positioning sleeve, replace the positioning steel ball, change the positioning spring
The 32. loader can automatically recover the bucket when the bucket is weak or the bucket is turned over and the bucket bottom meets the resistance.
Cause of failure:
Bucket cylinder seal is damaged, the large cavity had cut valve stuck or damaged, an overload valve stuck or damaged
Exclusion methods:
Replace the seals on the piston to clean or replace the corresponding parts
33. the phenomenon of noise produced by the hydraulic system, regardless of lift or bucket work, during the work of the loader
Cause of failure:
There is less hydraulic oil in the working tank, the 30 type working hydraulic oil tank vacuum valve is damaged or not tightened, the working tank is sucking oil, Guan Lao is chemical sucking flat, the working device is loose, the oil pipe clip is loose, the oil pump sucks the oil pipe intake, and the main valve on the work assignment is bad.
Exclusion methods:
Add the hydraulic oil to its standard value, tighten or replace the vacuum valve, clean the filter core or replace the oil pipe, and replace the main safety valve when the main safety valve is cleaned and repaired.
34. oil leaking from the rear of the positioning sleeve when manipulating the lifting couplet and the bucket valve stem
Cause of failure:
"O" ring damage of stem and spring seat
Exclusion methods:
Replace "O" ring and tighten
35. brake pressure is low and the brake is unflexible or unbrake
Cause of failure:
The air compressor is damaged, the pipeline leak, the compression pressure is insufficient and the multi-function unloading valve is damaged or adjusted, and the pressure is low
Exclusion methods:
Check and replace damaged parts or replace the assembly, check and tighten the leak, and shovel unloading valve or adjust the pressure to reach the standard value
36. the brake pressure is normal and the brake effect is bad or no brake.
Cause of failure:
Brake chamber bowl damage or air controlled cut-off valve damage, brake valve exhaust, brake hub and brake disc wear too much
Exclusion methods:
Replace the skin bowl or air controlled cut-off valve, adjust the gap or replace the brake valve, and replace the damaged parts
There is a different noise in the 37. brake
Cause of failure:
The hardness of the brake shoe is too large or the rivet is exposed, and the brake hub is clumped with metal debris between the brake hub and the friction plate, and the brake is overheated by the surface of the friction plate.
Elimination method
Eliminate the above phenomenon.
38. when braking, skew to one side
Cause of failure:
Two, the gap between the front wheel brake disc and the friction disc is different. The contact area between the front wheel and the friction disc of the two front wheel is different. A front wheel piston has air, a front wheel brake caliper is deformed, and the front wheel pressure of the two wheel is not consistent.
Exclusion methods:
Check the brake disc and friction disc, such as damage and replacement, check and replace the friction disc, discharge the air according to the correct method, replace the inflatable chamber, stipulate the air pressure and air pressure consistency, clean and blow dry.
39. brake pedal in the end, brake suddenly failure
Cause of failure:
The seal ring of the total pump is damaged or overturned, no brake fluid in the total pump, no brake pressure, serious rupture of the brake pipe or disjointed pipe joint
Exclusion methods:
Replace the damaged seal, add the brake fluid to the standard, clean the air in the oil road, replace the damaged brake line
When 40. continuous walking, the brake disc is seriously heated and the brake pedal is loosened, the loader is difficult to start the brake pincer and the piston is not back.
Cause of failure:
Loader brake pedal free travel or return bad, booster ring expansion or deformation of piston or piston is dirt stuck, accumulator return spring break brake piston on the piston ring damage or rectangular clip, rust, brake disc and friction plate gap is too small, the brake pipe blockage not sunken oil return the poor, the brake fluid viscosity is too large or too dirty to make the oil return difficult, not instantaneous exhaust brake valve
Exclusion methods:
Adjust the gap to the normal value, clean or replace the damaged parts replacement, return spring, cleaning or replacing the rectangular ring piston, adjust the gap or replace the friction plate a little thin, replace and dredge oil, cleaning or replacement of the same type brake booster pump oil, replace the brake valve or the speed gap
After the 41. hand control brake valve is connected, it is easy to pop out.
Cause of failure:
Low pressure up to 0.35MPa, hand control brake valve damage, sealing, gas control valve damage, parking and air chamber piston seal damage
Exclusion methods:
Check whether the air compressor is working or not, replacing the damaged seal
42. when the starting switch is connected, the starter does not turn
Cause of failure:
When the starter is damaged, the starting switch knob is in bad contact, the wire joint is loose, the battery charge is insufficient, the contact of the electromagnetic switch is not touched or burned.
Exclusion methods:
Repair or replace the starter, repair or replace the starting switch, check the fastening wire and charge, repair or replace the electromagnetic switch
43. the starting switch is turned on the starting switch, and it can not drive the engine to run.
The cause of failure is: the core of electromagnetic switch is too short, the armature movement or auxiliary coil is short circuited or open, the one-way gear is slipping, and the teeth of the flywheel are seriously worn or broken.
Troubleshooting: check and repair the electromagnetic switch or replace, repair or replace the coil, change the flywheel
44. the engine is idle or high-speed, and the ammeter is not charged.
Cause of failure:
Damage to the generator armature and field wiring insulator, ring insulation breakdown, silicon diode breakdown, short circuit or open circuit, voltage regulator contact burn, stator or rotor coil grounding or circuit breaker
Exclusion methods:
Check the damaged parts, replace the slip ring, replace the diode, replace the regulator, repair the stator or rotor coil
45. when the starting switch is connected, only the starter has a "rattling" sound, but it cannot be rotated.
Cause of failure:
The battery is not stored enough, or the wiring of the starting circuit is loose, the starter bearing is damaged, the armature shaft is bent (rotor part), the armature and the magnetic field coil are short circuited.
Exclusion methods:
The battery is fully electrically drawn, tightened and connected, and the bearing or starter is replaced. Check and repair armature shaft or replace starter, check repair coil or replace, start switch or electromagnetic switch.
46. bad cooling effect or uncooling
Cause of failure:
The electromagnetic clutch is not loose, the compressor belt is loose, the refrigerant is less, the condenser fan or the fan is not turned, the intake pipe is blocked.
Exclusion methods:
Check whether the electromagnetic clutch is damaged or adjust the belt. The loader sells 18504725773 refrigerant to its standard value, check the fan or line, check the intake pipe and remove the blockage.
47. air conditioning systems have noise
Cause of failure:
The transmission belt is loose or worn seriously, the compressor mounting bracket is loose, the blower motor is loose or worn, the electromagnetic clutch slips and the noise is released, and the internal parts of the compressor wear.
Exclusion methods:
Adjust the belt or replace, tighten the loosening part, re adjust, replace the motor or repair, check and repair the electromagnetic clutch or replace, replace the damaged parts, and replace the compressor when necessary.
48. engine cylinder cover around the "exhaust sound pops, water back to the water hole and with increased engine speed increasing
Cause of failure:
Because the cylinder fixed torque bolt is caused by the deformation of the cylinder cover, cylinder cover quality problems, early fuel injection advance angle
Exclusion methods:
According to the specified moment and order, the cylinder head is replaced, the cylinder head is rereplaced, and the advance angle is adjusted.
49. oil filling mouth and oil scale mouth out of oil
Cause of failure:
The oil sump level is too high, the oil pan (oil temperature is too high because of the high pressure oil-water separator blockage or crankcase ventilation holes to plug the individual cylinder cylinder piston ring, piston ring and cylinder liner wear serious bad seal, the high pressure gas into the oil pan)
50. engine oil consumption is high
Cause of failure:
The oil spill, turbocharger, air filter, oil filling too much oil grade does not meet the requirements, the oil viscosity is too small, the oil and gas separator blockage, air compressor piston, piston ring and cylinder liner wear serious, early wear gas channeling
Exclusion methods:
Replace the seal or tightening the oil spill site, the replacement of the supercharger, cleaning the filter, put to the specified location, change in conformity with the provisions of oil, cleaning or replacement, replacement of piston rings, piston ring and cylinder wall, cylinder and other parts replacement
51. oil is mixed with water, and the color of the oil is white
Cause of failure:
The water pressure to hold tight to loose Water Leakage or water blocking sucks, gasket damage or crack in the cylinder head, the body has sand hole, engine oil cooler or welding crack
Exclusion methods:
Change the water plug, replace the cylinder pad or cylinder head, replace the body, check and repair the oil cooler.
52. oil mixed with diesel oil and oil surface rise
Cause of failure:
One cylinder injector damaged needle valve card death, crack oil head burning and so on, high pressure pump internal leakage of diesel oil, oil pump piston seal ring damage
Exclusion methods:
Check or replace the oil cooler, check the injector or replace, replace or repair the high pressure oil pump, replace the oil pump
53. the engine smoked black and increased with the engine's speed.
Cause of failure:
The oil is too uneven or bad atomization, the cylinder pressure is insufficient, the combustion is insufficient, the oil enters the combustion chamber, the quality of the diesel oil is too poor.
Exclusion methods:
Cleaning the air filter to ensure the correct valve timing, fuel supply advance angle of fuel injection pump speed, piston, piston ring and cylinder liner wear serious injector should be replaced if the valve is not tightly closed should be grinding, check the oil-water separator, such as the turbocharger is blocked or damaged should be replaced, replaced with low-grade diesel, proper operation should be as sharp floorboarding will black smoke phenomenon
The 54.ZL50C loader is in the idle state, the moving arm drops and the lifting speed slows down.
Accompanied by a long working time, the working hydraulic system has a more serious heat.
Cause of failure:
Pilot pump overflow valve regulating low pressure
Lead pump overflow valve spool die or spring break
The efficiency of the pilot pump is reduced.
Elimination method
Reset pressure to calibrated value 2.5Mpa
Replacement of pilot pump overflow valve
Replace the pilot pump
Fault analysis:
The direct cause of the lifting and decreasing speed of the loader arm is the decrease of the oil flow rate for the lifting cylinder. The cause of low oil cylinder flow is that the efficiency of the work pump decreases, the actual oil supply is reduced, the two is that the opening degree of the valve stem becomes smaller and the three is the leakage point. The first and third reasons can be excluded because of the slow motion of the lifting and descending state of the above fault. The cause of the opening of the working valve stem is due to the machining deviation between the valve stem and the valve body. Therefore, the failure occurs at the time of factory leaving, and the problem is also becoming less and less with the improvement of machining accuracy. The second reason is that the pilot pressure is too low to cause the stem to be pushed out of the specified position. In actual measurement, it is found that when the pilot pressure is reduced to 13kgf/cm2, the speed of the idle speed will slow down to about 17 seconds. In actual maintenance, we should first remove the relief valve on the pilot pump and observe whether the spool and reset spring are damaged. If the normal pressure is adjusted after cleaning, if the adjustment effect is not obvious, it will result in the reduction of the efficiency of the pilot pump, and only replace the pilot pump. In addition, due to the decline in the oil capacity of the valve stem, the throttle at the valve port will cause loss, which will directly lead to the rise of the system oil temperature. This failure occurs, since the work in high speed accelerator, pump capacity is large, so the general feeling in the lift is not obvious, but when the drop is generally low throttle or idle speed, the oil supply is reduced, so the rate of decline will slow down significantly, it should be particularly noted in check when.
