Simple troubleshooting
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Excavator Troubleshooting 150 cases of classic...
Time: 2011-07-21 Hits: 5281
1 a EX200-3, the action suddenly the whole car shake, but only appeared in the excavator chassis at a slight angle in the case, such as excavators working in the ground is all normal. Started to hear this report, could not believe my ears. After the car arrived at the scene observed, excavation machinery at the workplace as a trench, fault really, as the report said. Found by the test machine, the machine chassis tilt jitter occurs, once the excavator to open a flat work surface to work, shake ceased. Are repeated so many times. EX-Docder display, jitter A big, sometimes small, does not shake when A is also normal. Check all external components normal. At this point it was late, agreed to close down on battles.

The next day arrived at the scene, check the wiring harness from the start, because on the eve analysis: each component is no problem, whether the problem is poor contact on the line. First check the wiring harness near the pump, and found: A hydraulic pump at the bottom for the fixed sensors and other components, wire harnesses steel clamp has worn, exposing the copper wire. When the chassis is just sitting side when steel and copper wire clamp contacts, leading to short-circuit. And hydraulic shock due to take time off so that the two time jitter caused by the action; while the chassis is sitting when the distance between the two can not touch. So working properly.



2 A modern R290LC, working hydraulic system oil temperature high. No-load detection system that emperor pump pressure 10Mpa, engine rated-load pressure transmitted over 20Mpa, and after working the pump side of the actuator speed is full. Analysis that such a contradictory phenomenon. First check the no-load voltage problems; multi-way valve after the pump side of the non-catching position is not in the phenomenon, is not prone to stem valve in place of the spare pump side of the front, and this has nothing to do. By understanding, hydraulic main pump recently been overhauled, it is suspected the pump variable emperor may release the shift fork, resulting in a smaller displacement swash plate position. This can explain the speed of full problem, since the pressure in the smaller displacement Why higher?

Decomposition of the main pump, release the shift fork that really variable, resulting in a smaller displacement swash plate position. Fastening force due to lack of safety regulations and did not increase due to thread locking adhesive. Check the test machine after the repair, there are still no-load high-pressure phenomenon. Analysis of the hydraulic system diagram, that causes a high pressure pump dry mouth the biggest reason is that the logic valve b, b if the no-load pressure signal port extra, you can cut off the main circuit caused by high pressure. Loosen and disconnect the signal b port tubing, start the engine check, there are still high. Logical study of the structure found in the throttle valve rear filter, disassembled see cause foreign body has been blocked filter, installed after the removal test, everything is normal.



3 a Carter 345B, boom partial gap welding work, welding parts in a rotating platform Ground, and the power switch off. After starting the engine, the engine running for about 1 minute to automatically shut down, then starting again, the engine does not work, but the starter is working properly.

Aircraft engine high-pressure common-rail EFI, Model ---------



Check fault codes: no exception.



4 a Komatsu PC200-5, machine for two phones. Reflect the owner bought the aircraft from the slow recovery after the stick.

By the test machine, in addition to Stick to recover the remaining ministries are outside the normal slow. In general, if the boom should be accompanied, bucket, walking or moving arms, turn, walk full of the phenomenon. By comparison the hydraulic system diagram, that Komatsu and other firms, the circuit has a flow valve called a half stick of solenoid valves, designed to switch the stick back when the main pump or two single main pump oil.

Check the solenoid valve, do stick action to recover the signal is working properly, you can export oil solenoid valve. Decomposition of the valve, that valve P, T, A port tubing installed anti-normal working hours of the confluence into a single two-pump pump flow. It is little more full. Properly installed P, T, A port tubing after the test machine, Stick to recover normal operation.

After the observation aircraft maintenance, found the body on the English word "crane style" text description has been used for lifting work, likely for Japanese companies for crane work, deliberately modified to Stick to recover the action becomes full, so When fine-tuning to adapt to lifting action.


5 a Hitachi EX300-5, suddenly turning slow motion, also found that the level of non-stop walking and the whole car automatic throttle.

Reasons: the pilot filter hydraulic oil exports nearly all the way into five bar group multi-valve, used to provide brake pressure of the oil and rotating the entire vehicle automatic throttle signal oil. Inlet pipe joints have a filter, the filter plug after making these two very low pressure.

6 a Hitachi EX200-5, the line suddenly no lower gear, high gear only.

Reason: the level of walking within a filter block, the block filter, a variable piston motor running can not be released back into the oil tank, variable displacement piston motor running when the minimum work, it has been in high gear status.



7 a Hitachi ZAXIS330, suddenly the whole car hold car, because: pilot filter clogging.



A Hitachi ZAXIS200, a full-speed action pump side of the powerless. Manifold within the pump control pilot valve spring failure.



8 a Kobelco SK230-6, the user reflects the sudden deviation walking, wandering, and not only by checking the speed of a pump full of action side weakness. Note reflects the phenomenon of mechanical failure points: the true and comprehensive. Reasons: a pump control valve resistance larger.



9 a Kobelco SK230-6, instrumentation and sometimes alarm, pump control solenoid valve malfunction display, reasons: the bottom of the hydraulic pump wear drain wire conduit card.



10 a Hitachi EX200-1, left unable to walk at least, reasons: the left front one-way valve multi-valve damage



11 a Hitachi EX200-1, the right to walk away full of weakness Boom Stick bucket full of reasons: to walk the right side of multi-way valve at the card a piece of metal valves



12 a Sumitomo SH200-1, a sudden walk to the left deviation. Reason: solenoid valve spool catching and stay in the work place, cut off the normal feedback pressure pump, the pump cylinder tilt angle minimum. It is part of the action becomes full.

13 a Hitachi EX300-1, raise the air when the boom suddenly sank for some, and then rise due to: multiple valve stem 2 of the load boom one-way valve damage.



14 a Sumitomo SH200-1, suddenly the whole car is no action, because: the pilot solenoid valve coil burnt.

15 a Sumitomo SH200-1, a Sumitomo SH200-1,

16 a Kobelco SK200-5, there a variety of dashboard warning, reason: reason: the generator damage

17 a Hitachi EX200-3, there dashboard oil pressure, charging the police, and unable to control off the engine, the engine stopped, power key can not, because: generator damage.

18 a Sumitomo SH200-1, the entire vehicle speed very full, reason: oil control solenoid pilot valve damage.

19 a Kobelco SK200-5, one side full of weakness, reasons: the lower part of the cab a valve solenoid valve damage.

20 a Sumitomo SH200-1, clear the whole car hold car Morning, check the hydraulic circuit to normal. It was learned last night, fog, humidity, air filter intake suspected problem, the owner made yesterday afternoon, even just for new products, there can be problems. Strongly urge the removal of air through the filter test machine, everything is normal. No description of the quality of the air filter. When the air humidity, the paper inflated, blocking the filter holes.

21 a Sumitomo SH200-1, facelift Korean independence after the hydraulic pump assembly, the side of the car moves hold the other side of the pump maintenance personnel replaced the regulator spring, in exchange for normal work after the original product. Shows sometimes dress pump P-Q curve characteristics are different.

22 a Kobelco SK200-5, engine overhaul, the entire vehicle a very full speed, engine speed is no fault code shows the full speed after troubleshooting. Then suspect that your computer board problem. Other bug fixes PC board installed after the test, the fault still. A line is not adjusted. Then replace the ROM, the ROM fault found in different models different, and some non-reflection, the same fault with the original; some boom lift automatically when the stick protruding; only the correct ROM machine was working properly.

23 a Kobelco SK200-5 `5, sudden boom when the bucket lift lever automatically extended, the other is functioning normally. Trouble-free instrument panel display, no problem by checking the hydraulic circuit. Suspect that your computer board failure, replaced after a PHUD4432 normal, that for some reason, the ROM program memory is lost. A description of the instrument panel does not appear fault fault code.

24 a Hitachi EX200-3, multi-valve replacement of seals, the entire car without action. Reasons: the electromagnetic valve of P, T mouth upside down.

25 a Hitachi EX200-3, after multiple valve replacement seals, walking around full speed becomes weak, and no walking becomes blocked. Reasons: the pilot control valve at the pipe installation and backup running anti.

26 a Hitachi EX200-3, using a hydraulic hammer work. Hammer work full speed very suddenly, about ten seconds to move, unable to cut. After checking the hydraulic hammer itself, no problem. A spare valve compensation valve does not work after the first catheter is disconnected. Tank with a three-way to access, troubleshooting. Reasons: due to certain factors, electromagnetic valve back valve to the pilot through the compensation valve oil, resulting in compensation for one-way valve within the valve closed, so the abnormal movements.

27 a Kato HD820, suddenly filled the side of action. Reasons: the small pump regulator valve stuck.

28 a Kato HD820, the whole car is full. No fault code display. Suspect that your computer board failures and found a burned electrical group, even after replacing new. Check the pump low pressure proportional valve control, adjusted to normal.

29 a Carter 320B, the whole car full speed. Proportional valve to adjust the pump control valve and pump torque is also invalid, not action is fast but choke full of cars. Use of the machine parameters of the computer check and found that the level of the proportional valve controlled pump start point pressure is not correct, according to the 320B manual fitting parameters correctly adjusted successfully.

30 a Carter 320B, suddenly hold back car, check that no addition to the level of failure to go further outside the block phenomenon. Suspected electrical fault. Dashboard program check no engine speed, new speed sensor replaced after the fault is not excluded. PC board check OK. Focus on examination of the line, toe-boards that will pump about 20 or so a harness squeeze off five, right after the two failures are in addition connected. Appear

31 a Carter 320B, suddenly dashboard display from time to time, the line judge should lift the poor, according to the circuit diagram check: Insurance to the dashboard of the normal line, insurance normally observed to a computer circuit boards, observe the PC board two plugs , found on the right a more loose, tighten again after the failure does not appear. Post-mortem analysis of loosening of the plug should be bad, when the excavator is sometimes displayed when vibration-free phenomenon.

32 a Hitachi EX200-3, no sudden dashboard display, power and insurance, no problem. Suspect dashboard itself. Without dismantling the internal water corrosion, inspection with a magnifying glass, the lower part of the power supply circuit board printed circuit has a crack, welding after the test machine to normal.

33 a Hitachi EX200-3, hold car. EX tester found, P sensor data is incorrect, the understanding of other staff have repaired the line. Test results: P sensor signal line and ground lines reversed, after the normal response.

34 a Kobelco SK200-3, an intermediate of the main pump check valve upside down.

35 a Hitachi EX200-3, work on hold for about an hour car. A sensor failure, proved cooling with cold water.

36 a Sumitomo SH200-1, a sudden unusual noise hydraulic pump, check the fuel tank has a lot of bubbles. The main pump shaft oil seal damage.

37 a Sumitomo SH200-1, the engine stopped, the hydraulic pump at the unusual irregular "Dangdang" sound, and increasing the past few days, flexible coupling damage.

38 a Sumitomo SH220-1, diesel pump deterioration, proved cooling with cold water.

39 a Carter 320, suddenly the whole car is no action, all the flexible coupling of the four bolts off, causing the main pump and the pilot-free hydraulic oil.

40 a Carter 320, a variable piston pump wear,

41 Komatsu PC200-6 a hot car slowly, the main safety valve wear. Grinding repair

42 Kato HD900-7 of a sudden the car is no action, but the normal walking

More than 43 one-way valve for Sumitomo S280 to win the title, no action on one side, pump feedback valve fitted with overload valve counter-

44 Carter E200B a pump a load of high pressure, the pump repaired, the variable feedback lever nut too tight, the lever stuck

45 a Hitachi EX300-1, pressure pile driver to use. Full rotation and left walking. Stem upside down.

46 a Hitachi EX200-2, suddenly the whole car moves very slow and weak, and the system pressure test A small 10MPA, the main valve of the main spool is damaged O-ring particles blocked, pressure can not be increased.

47 a Hitachi EX200-2, suddenly the whole car moves very slow and weak, and the system pressure test A small 15MPA, the main valve of the main spools are foreign body pad to live, the pressure can not be increased.

48 Sumitomo S280 a sudden the car without action, but to walk normally. The main pilot valve spool is damaged O-ring particles blocked, pressure can not be increased.

49 Carter E300B a sudden the whole car moves very slow and weak, the main pilot valve spool is damaged O-ring particles blocked, pressure can not be increased. Pump A8VO107

50 of a rotary drilling machine Hitachi 600 suddenly the whole car moves very slow and weak. The main pilot valve spool is damaged O-ring particles blocked, pressure can not be increased. Beams within the pilot valve in the right front to back 2 / 3.

51 One side of the main pump Alcatel E300B weakness and associated pump and slow abnormal sound, the oil pump with oil pan out of the mouth upside down.

52 a Hitachi EX200-5, the rotary motor work, a sudden rupture of the motor housing, replacement of two new series, still broken. The owner is extremely distressed. The analysis may be too high internal pressure caused by the motor, check motor oil drain and fill loop, found to be foreign body within the motor drain line blocked, only by very little oil. It can use just for a while after the new.

53 a geotechnical auger machine, oil temperature close to 85 ¡æ, the main winch and side walk slow and weak. In particular, can not raise the standards of the main hoist rotary drilling equipment. Flow meter testing, load testing: hydraulic pump, no problem. 40 to 70 degrees the normal flow pressure, 85 ¡æ after the pressure and flow is not normal, indicating that the multi-way valve in question. Analysis of normal system flow diagram, and so on. . . . .

54 a Hitachi EX200-3, installation of hydraulic hammer, hammer work properly after the installation is slower and weak. Test loop pressure and flow, the hydraulic oil flow is very small hammer, excavator bucket, when properly used. Carefully checked and found the new machine spare valve stem is a small adjustment screw in position, properly adjusted after the OK.

55 a Sumitomo SH200-1, start working, after about ten minutes the whole car hold car, spare valve stem displacement.

56 a Sumitomo SH200-1, a special guide lines, loose on a multi-way valve after the first catheter, normal.

57 a Sumitomo SH200-1, no-load collection vehicles choke the engine Stick, Multi-way valve inside the stick to keep the valve wear.

58 a Hitachi EX200-3, when the engine choke down boom cars, boom to keep the valve wear. Remove the valve.

59 a Hitachi EX200-5, no-load collection vehicles choke the engine when the stick, the aircraft is equipped with cranes and ancillary pipe valve. Stick a small chamber to keep the mouth of the valve spool wear working. Remove the spool.

60 a Hitachi EX200-3, PC board is damaged, check the system short circuit caused by external components. Also replace the A and board.

61 a Hitachi EX200-3, suddenly hold car, check no 24V power supply high-speed solenoid valve, relay # 2 does not work. Analysis of their works. 2 # relay the signal from the PC board under the control of its external switch, such as the aging of high-speed solenoid valve can cause this failure, but this time can still use high-speed solenoid valve, so short the # 2 spot with its normal power supply relay method troubleshooting.

62 a Hitachi EX200-3, suddenly the whole car slow. No high-speed solenoid valve check 24V power supply, still restored. EX diagnostic DP signal is not normal, replace the new DP after the OK.

63 a Kobelco SK200-6, dashboard warning but not see the content, the failure phenomenon of the side of the slow and weak. Check the circuit after the pump system and found that the lower part of cab No. A solenoid valve solenoid valve plug loose, the valve is cut off solenoid valve P2, can cause the failure. After the plug is working properly.

64 a Komatsu PC200-6, the hydraulic system oil temperature high. New replacement oil radiator is also invalid, the machine work ten minutes later, hand-to-oil import and export of steel radiator, feeling the large temperature difference, indicating the hot oil without the oil cooler. Analysis system map that the oil cooler into one of the two-way valve problem, dismantling the # 1 check valve, valve spring is broken, a lot of oil return to tank from here. After replacing new normal.

65 a Hitachi EX200-5, the side of the work slow and weak. Inspection found that the pump flow control valve without 24V power.

66 a Hitachi EX200-5, left to walk slowly. EX check the low pressure pump flow control valve, dismantling the 5 side of the Ben-controlled valve stem, the top of the spool valve sets have been ground into an elliptical hole, after replacing new normal.

67 a Hitachi EX200-5, the throttle motor suddenly out of control, and sometimes power high-speed, sometimes not start the engine, so turn off when the throttle lever is in position. Reason: hydraulic tank and wiring harness friction, leading to Ground.

68 a Hitachi EX200-5, the throttle motor suddenly out of control, because: throttle motor center hole in rubber gear and a motor shaft slippage relative rotation,

69 a Hitachi ZAXIS330, sudden weakness on one side slowly, the pump flow control solenoid valve damage.

70 a Hitachi EX200-5, hydraulic system oil temperature high. And cause water temperature high. Water tank that is normal for one hour boil. Not work. EX checking two large swing angle of the pump, but pressure and tilt angle normal load. Initial pump control board computer to determine the output part of the exception. Suggested a change of the hydraulic control system OK.

71 a Kobelco SK200-5, dashboard displays "starting point exception" and "current anomaly", check that the throttle without the motor limit switch 24V power supply, combined circuit. 20 # Insurance burned, replaced after the new normal.

72 a Kobelco SK200-5, engine overhaul, the entire car is slow. Check engine speed, throttle maximum speed is only 1400 rev / min, according to the specification after adjusting the throttle motor correctly.

73 a Kobelco SK200-5, suddenly the whole car was slow, and bring up the computer programs work and found the engine speed is zero, check the speed sensor and wiring harness, wiring harness properly, measure the output of the sensor without AC, and then measure the resistance 0. Coil inside the sensor circuit. 320 with a sensor instead of Carter, installed after the OK.

74 a Komatsu PC200-5, suddenly the whole car was slow, and the pump control computer board display fault code: 17. Of the engine speed is a problem, check the speed sensor and wiring harness and found a wire off the sensor, connected to normal.

75 a Hitachi EX220-3, grab the machine for the telescopic arm. Often does not move a motion of the phenomenon. The analysis is most likely the solenoid valve. The body is made of aluminum alloy casting, the action of return spring force smaller, slower flow rate of the valve body oil, and any foreign objects stuck easily harbors the core. After thoroughly cleaning the valve installed, there have been no more than three years before the failure.

76 a Kobelco SK200-6, enhance the boom when suddenly the sharp drop in engine speed, while improving very slowly. Intuitively suspected boom raise pressure sensor failure. Test machine that: even if you cancel automatic idle function, the boom speed is not changed. First check the sensor with the same sensors instead of the other, boom return to normal and abnormal movements being replaced, the sensor problem. Replace the new OK. This auto-throttle pressure sensor not only pass the signal, but also continuous operation pilot pressure signal is passed to the PC board, according to other external computer and then send commands to the integrated information solenoid valve, so that the machines work properly.

77 a Carter 320, no sudden movements on one side. First check the pump vibration and noise associated normal, followed by the check back to the oil filter and no metal powder particles, related to the discharge hole to put the oil pump, no metal powder and granules. Description of the rotary pump assembly is not damaged. Therefore, the initial feedback signal to determine the pump or pump displacement controller failure.

Swap out two main pump tubing and feedback control, the failure to appear on the other side of the action, indicating that the pump itself is indeed a regulator problem. Dismantling the regulator found, the big spring cavity feedback has been cut off three small servo valve¡¯s return spring is broken, and there is a card in the spool and the valve hole.

Due to large spring break, the feedback spool position feedback pressure equivalent to the highest state. So the whole trip when the main stem, the lowest pressure at this time feedback feedback of spool position and will not stretch the spring under the big return, the smallest displacement.

After replacing the size of the spring test machine, everything is normal.

78 a Hitachi EX200-3, suddenly the whole car is slow. # EX examination revealed a high-speed solenoid valve does not work, remove the solenoid valve and line of reason, determine fault should be on the computer board.

Check the computer panel, power control has been found Q6 burned, replace a new tube, the machine properly.



79 a Hitachi EX200-5, when the engine suddenly received Stick hold car. Arm extension machine when the sound is not right. Generally speaking, this failure is the stick to keep the valve stuck due. Dismantling the valve, no problem. Suspected cylinder head guide sleeve shift, to block the oil port. Because there have been other brands out of the failure of the excavator precedent, but the Hitachi has not appeared.

Open the cylinder head ports, it was found that a spherical object blocking the port, watching carefully indeed oriented sets. Normally blocked by a steel ring Sika, will not move. The world seems to think things will happen ah.



80 a Sumitomo SH120-2, Multi-way valve seal replacement, the engine, once started, automatically lifting the boom.

Check the pilot system, no problem. The analysis diagram: there may be pressure to enter the main boom confluence valve. Dismantling the mixing valve and found it stuck, finally open, and then found that the assembly of one-way valve assembly with spring loaded against the spool, where judgments are easily installed by conventional anti-. Test machine OK.



81 a Komatsu PC200-6, reflecting the boom to enhance the main machine slow.

The actual manipulation checks: In addition to enhancing the slow boom, the stick back and slow. Boom and stick cylinder sagging phenomenon was not found, other actions normally.

Test the main pump pressure: raising the boom all out, the first pump pressure 3.2 Mpa, the pump pressure 32 Mpa; stick full back, the first pump pressure 32 Mpa, and the pump pressure 3.3 Mpa. At this point the test conditions for the two-pump operation confluence, can be judged accordingly to enhance the boom and stick back when the pump is not double-confluence.

Control hydraulic schematic: double pump or by the combination of actions and the confluence of workers at its option, the electrical signals transmitted to the computer, then send a signal to control the pump from the computer confluence - diverting solenoid valve action, controlling the main pump combined diversion.

First check the boom raise and stick back pressure sensor, the sensor is normal.

And then double-check the pump for the confluence of improved working conditions, such as when the boom confluence - shunt valve outlet pressure, then exit without pressure. Computer instructions may be a signal abnormalities; solenoid valve itself may be a problem.

With a multimeter to test the computer signal. 200V DC test file with the confluence of two-pump when the boom to enhance the value of the time-to-ground voltage 24.6 V, when the double-pump diversion boom to enhance the value of the time-to-ground voltage 0V, is normal.

Decomposition of the solenoid valve, that valve has been bent and stuck the needle in the valve body, always in the shunt position. Normal replacement.



82 a Hitachi EX200-1, left the motor running out of the floating seal several times.

Upon inquiry: the central rotary joint seals have been replaced several times.

The usual reason is because the leakage of oil running motor circuit resistance caused by too much.

Check walking two motor oil pipeline leak out. Further examine the central rotary joint, found the holes on the pressure plate is not connected with the shaft back to the hole. Therefore, malfunction rotary joints for the replacement of the central location of the pressure plate when the seal is not placed correctly, walking motor oil leakage circuit was closed, leak pressure when the motor shaft oil seal out subsequently destroyed the floating seal. Correct installation troubleshooting.



83 a Hitachi EX200-1, rotary and left unable to walk.

Found in a separate test machine operation or left turn when walking slow, weak. At the same time enhance the recovery of the boom or stick to the end of travel or when turning left to walk fast and powerful. Shows no problems after the pump failure in the control valve.

Analysis of the hydraulic schematic: failure to stick to accelerate the valve between the control valve and check valve damage. New replacement after troubleshooting.



84 a Hitachi EX200-2, excavators found just under the dashboard after the flatbed trailer without electricity. Engine failed to start.

Check: Turn the key switch to the ON position, the battery can hear the relay "click" sound, indicating the current has passed the relay. But the dashboard does not light, switch to the START position when the engine is still not start. Carefully observe the battery positive pole pile with cable access to the weak spark at the smoke, because the excavator off the shock result when the positive pole pile and the cable is bad. Correct connection troubleshooting.



85 a Hitachi EX200-2, all cars slow, weak.

Upon inquiry: the owner had just replaced the pilot reflects the pump seal, but the replacement has been working for ten minutes is normal, then suddenly die. Under this situation, the first suspect the pilot pressure is insufficient.

The low pressure test pilot, the pilot decided to break down the pump.

First found in the skeleton of the pilot pump input shaft oil seal has been out of this for two reasons: First, install, and second, where the pressure is too high. Continue to break the seal found in the direction of the pilot pump upside down. Here is the real cause of failure, when beginning work, oil seal is not completely damaged, can still work, because oil seal can withstand low pressure, it will soon damage the seal, causing the pilot pressure oil from the defects escape.



86 a KATO HD700-5, no right-lateral movement and bucket, boom and stick slow.

Upon inquiry, the control valve assembly in the complete replacement of the seal after the failure occurs. After measuring the pressure when the pump bucket collection for the 1.5 Mpa, far less than the normal value of 28.5 Mpa. Two-way exchange in the preparation of a safety valve, they found fault on the side of the valve position as a plug and the original location of the plug valve was installed. The correct position after switching the machine properly. The original maintenance personnel replaced the control valve assembly sealed, the group¡¯s safety valve and the valve plug position upside down.



87 a Hitachi EX200-2, failure: the action is not flexible; walk, regardless of the high middle and low, are all mid-range.

EX-doctor diagnosed with various parameters, showed no action when the pressure of pressure sensor gives the signal to 0. Dismantling the pressure sensor, pressure sensor diaphragm has been broken and replaced after the new normal.



88 a Carter E 200B, for 15 minutes, turn and left to walk slow, weak.

Following the exchange after the pump outlet tubing to determine the post-pump failure.

After dismantling the discovery of variable piston pump and the pump casing wear unusual, small end and big end of the piston are worn. The concentric holes in the boring process, re-equipped to do the Pistons, spotting installed for testing after 6 hours, confirmed that the fault has been ruled out.

Failure Analysis: According to the principle of the variable pump, when the maximum no-load variable, the variable surface of both ends of the piston-based pump pressure, the piston is worn, wear the same under the big end of the vent piston small end big oil than piston, pressure is lar, , ge enough to force institutions to small variable direction. Feedback mechanism will be replaced by small end of the pressure piston big end oil return status until the point of running to a minimum displacement. And when there is maximum load displacement, normal variable piston should move to a small variable equilibrium position, the piston force at both ends of the same. However, due to oil spills caused by the pressure to balance the damage variable and has been moving up to the small end.



89 a Carter E 200B, turn the brake when the impact of other normal.

Apart from the test machine and found the brake, the rotation in the middle of the process is still normal, and the same forward and reverse rotation. The failure has nothing to do with other parts.

When the check valve in the left-hand turn when the pilot was found among the bits of the two rotary pilot valve ball is also pressure the pressure plate, no clearance volume. Therefore, the correct amount of adjustment after the failure to eliminate the gap.

90 HD700 -5, after starting the engine Stick cylinder rod retracts, the other is functioning normally. After examination, a normal rest of the action; two Lift Boom Stick after sinking fast. Stick the first catheter exchange after the fault persists, indicating a fault in the control valve, or Stick Cylinder, in line with the principles of the easier issues first. Dismantling the control valve stem, the stem is stuck in the piston rod retracted position, and the brass rod with a rubber mantis head out after the shock stem. Have seen the end of shiny iron, contact Stick sinking fast. Determine the root cause for the bucket cylinder rod strain, dismantling Stick Cylinder confirmed.

91 EX200-3, machine No. 14C-62621. After installation of the hydraulic hammer, hydraulic hammer does not work. Check the correct installation of pipe, working pressure is normal. Access to technical information found after the machine: the machine back flow valve stroke is controlled by an adjustment screw. Machine factory trip state is 0. After the correct flow regulating hydraulic hammer works fine.

92 Ex300-3, machine No. 15L-7616. Boom down too fast, when the boom to enhance "nod." "Nod" failure is usually the load control valve inlet check valve is damaged, but the inspection found no problems. Combined system diagram analysis: failure to accelerate the boom control valve and its valve between the check valve failure. Dismantling confirmed.

93 PC200-5. And right turn suddenly within a few minutes walk no. Tubing before the pump test found a strong vibration, check the oil filter tank back to the end of a large number of copper and iron. Place before the oil pump case also copper and iron at the end. Seriously damaged the front pump.

94 SK200-5. Suddenly the whole car moves slowly, the speed of standard operating speed of 1 / 5. Engine is working properly. Damage to the engine failure speed.

95 SK200-5. Suddenly the whole car moves "choke car", after inspection, discovered the variable pump PCV valve does not work, because the solenoid valves and the connection between the computer board as a vibrating machine, wiring harness plug loose, resulting in open circuit.

96 PC200-3, the whole slow-moving, hydraulic pump abnormal sound.

After examination, the hydraulic oil tank at the pump inlet filter on a large number of scraps of paper. Clean up after the machine is working properly. Work about 30 minutes, turn and walk and move the right arm and arm movements slow. Other actions normally.

Exchange after the main pump outlet hose, bucket and left-lateral movement very slow, indicating that the first pump failure or its institutional variables. The variable valve body cleaning machine is working properly.

97 PC220-3. Suddenly the action bucket and left to walk slowly, after the exchange of the main pump outlet tubing, turn and right-lateral and boom and slow action rod with a separate method for detecting faults in the pump confirmed institutional variables. Dismantling the institutional variables that variable piston fork pin drop. After re-install properly.

98 PC200-3. Engine for about 2 to 3 minutes, left to walk slow. Check that the engine load when the sound muffled, with a load seemed to work.

The test pump outlet pressure, the engine just after starting, before the pump load pressure 1. 3MPa, after the pump load pressure 1. ZMPa. But 2 to 3 minutes, the first pump load pressure 1. 3MPa, after the pump load pressure 30MPa. According to the schematic analysis: pressure change after no action of the implementing agencies, the pressure generated by the system can only come from an alternate valve action. Remove the back ends of the pilot control valve tube fault disappears.

99 PC200-5. Two phone lines, used 3 years from the purchase after the discovery work and raise income Stick boom slow, the other normal. After examination, the Department Stick semi-flow valve has been artificially altered to restore the original system is working properly.

100 PC200-5. Crawler weakness, no line of lower gear. Replacement of the central rotary joint sealing, the fault still. Check the walking speed solenoid valves for the oil found in the dirt stuck to the spool. Cleaned properly.

101 CAT200B. Suddenly left to walk forward without the other is functioning normally. After examination, the Department left the motor running overload valve spool is paving the dirt, resulting in inability to move forward.

102 PC200-5. No sudden turn, the other is functioning normally.

Check: Start the engine, release the brake control pipe rotation and found no pressure oil pipeline. Description from the rotary brake valve outlet pressure is not normal, there may be two reasons: first solenoid valve spool may be stuck in the closed position, the pilot oil can not: the second solenoid valve coil circuit may be unable to open the valve. Coil resistance with a multimeter measuring the resistance to 0, the normal value should be 15.5?. Normal after valve replacement.

103 PC200-3. Machine for 10 minutes, the hydraulic system at higher temperatures.

Upon inquiry, the aircraft has been in heat since the purchase, especially in the summer, operating speed and crowding force decreased significantly affect efficiency.

Machine inspection, the work pressure is normal, the main components of the main pump machine has replaced new.

Hydraulic oil radiator cleaned. And out of touch the radiator hose and found a higher inlet temperature, and outlet temperature is lower. Description hydraulic oil radiator is not working. Control diagram, the radiator may be clogged; safety valve may be damaged. The user reflect the radiator has been cleaned recently.

Check the safety valve: The valve is located in the bottom of the tank back to the oil filter with needle nose pliers remove the valve, found on the spool valve, spring and lock the mother has disappeared, according to the schematic configuration of the spring data, processing spool, assembled and installed on the machine. At ambient temperature under 34 ¡æ for six hours, hydraulic oil temperature is normal.

104 UH07-7. Left-arm slow walking and moving.

The actual manipulation, Chuzuo slow walking and boom, the stick and slow. After the initial judge of the pump displacement is less than the previous pump. After the pump to adjust the displacement increase.

105 Ex200-1. All action "choke car." Due to the absorption of the pump power is much higher than the engine power. Institutions in the two pumps will pump the variables constant power curve after re-calibration of the machine properly.

106 EX200-1. Rotation weakness, right-lateral weakness, inability to boom support vehicle. But at the same rotary control, walking stick or left boom support vehicles strong. Determine the initial 1-way valve failure. Dismantling confirmed.

107 MX8. Sometimes, when no-load back bucket cylinder engine overload.

The inspection excavator bucket cylinder fully loaded when no exception. The sub-pressure measurement, pump and control valve to normal. Fault in the fuel tank. Dismantling the cylinders have been found to guide sets out in situ, when the guide sleeve when the piston rod back to the rod chamber port blocked. Analysis that should be added in a ring within the cylinder head to prevent the guide sleeve movement. Is a design flaw.

108 PC200-3. There the whole day working very slow. Check: Test TVC valve outlet pressure of about 0.5MPa, far less than normal. Test Pilot pump outlet pressure 3.4Mpa normal. Check the pump outlet tube leading to the main pump housing of the filter and found that surface has been fine wire plug. Installed properly after cleaning.

109 EX200-2. The cylinder moves with creeping phenomenon, the whole force is small, the system heat. Adjust the main pump flow and system pressure after the invalid. Try a large machine that loads when the pump or cylinder stroke in the end an export pipeline abnormal vibration. Judge for the pump internal failure. Dismantling the pump: oil pan found with severe copper surface spalling.

Replacement parts and repair the main pump. Test machine to normal.

110 EX200-2. Found within a few minutes the main pump outlet tubing sudden strong vibration and abnormal sound.

According to experience the main pump failure. Demolition review found that: after the ball plunger pump seven were forcibly pulled out the whole ball and socket, which killed a plunger in the cylinder body. Emperor of the pump rotating assembly scrapped. Replace the new cleaning system after the test machine to normal.

111 PC200-3. Suddenly complained of left-lateral machine does not move, and the remaining normal.

By the test machine, Chuzuo walking around the rest does not move outside the normal.

As the system for the mechanical manipulation of walking, and bucket and boom of the normal force and speed, so the issue should be excluded from the pump. Found in the test machine or a few times when violent manipulation of air support from the left-lateral rotation and manipulation of a sudden turning movement, the occasional walk with the action left but soon disappeared.

Careful analysis of the hydraulic system diagram found that manipulation of the left walking alone, the pressure oil pump may be right before walking into the circuit. If the right-lateral load check valve is faulty, then the fault characteristics of each line.

Dismantling: the end of the load check valve broken.

When a sudden turn or stick to manipulate the action, the valve may be reset, resulting in occasional left-lateral movement. Normal replacement.

112 PC200-5. Turn and right-lateral movement and the beginning of the end of major impact. In addition to rotating the test machine and found that the right to walk from the brake, the middle of normal operation, the remaining actions are normal.

Before the pump test data of each measuring point. Which found that when the no-load speed feedback pressure Pd = 0.2MPa, Pt = l. 3MPa, just take the anti-Pd and Pt. When properly installed on the machine properly.

113 PC200-3. The action "choke car."

Test machine that even the bucket-load, including all the actions are "choke car."

Check the feedback control valve to the pipe and found that Pd and Pt before and after the pump is reversed. When properly installed on the machine properly.

114 E200B. Suddenly unable to walk and turn left.

Upon inquiry: failure process only a few minutes, also found that the emperor of the pump outlet tubing jitter, abnormal sound.

Preliminary view that the main pump failure. To avoid further contamination and failure to extend the system, not the test machine.

After removing the oil pump housing block release, with the end of the oil out of a lot of copper and copper block. After the pump has been damaged. Replace the new cleaning system after the test machine to normal.

115 CAT320. Bucket and the right to walk gradually slow down.

Check that the machine oil higher, but also cooler operation, the failure should be independent of temperature.

Also found that every time the engine shut down, there are always several more at the pump, "Kaka" abnormal sound.

Check that the former variable piston pump installed state, can be hand-drive variable piston front about 10mm, and feel no resistance. Under normal circumstances more difficult to promote. Removed before the pump before the pump is seen after variable swing frame and variable piston pin junction is shocked into an oval hole, so that the maximum pump displacement smaller, bucket, and the right to walk gradually slow down.

Also found that the flexibility of flexible coupling on the block damage. Namely, the reason for the abnormal sound.

Put the variable and variable frame repair its replacement piston pin flexible coupling. Test machine to normal. Analysis: The lead pump each time the engine stopping once to bear the impact of the former junction of the variable pump damage.

116 CAT320. Bucket and right-lateral movement suddenly within a few minutes slow.

Test the pressure is normal. Before the fuel tank and hydraulic pump case no metal powder, a preliminary judge for the former variable body pump failure. Before dismantling the pump is found: the feedback signal flow pressure valve spring and set back spring break, the former variable piston pump is always in the minimum position. Replace the product after the test machine to normal.

117 EX220-2. Two crawler weakness.

By measuring both sides of the walking pressure 22MPa. According to the owner to reflect, and sometimes also high-end speed serial block walk phenomenon. Thus can be a preliminary judge for the central swivel joint seal damage. Demolition review found that: The oil seal has become a dark brown granular road. Replaced with new sealed, the pressure of walking test 35MPa. Test drive two hours working.

118 SK200-5. Normal operation, the oil pressure suddenly alert.

Examination: normal oil level, oil pressure sensor to the computer wiring harness between normal. Detect oil pressure sensor is normal. According to the onboard computer of the alarm, control maintenance information to determine the cause of the malfunction is the oil filter clogged, causing the oil filter on the pressure sensor alarm. Change your oil and oil filter after the troubleshooting.

119 EX200-2. Rotation weakness.

Test machine that turn and increase the revenue boom or bucket when the rotary rod in the end a little faster, but still feeling weak.

Rotary motor working pressure test, the test point for the valve outlet. Turn around when the pressure are 11MPa. However, other actuator is working properly, the EX200-2 system works analysis shows that the pump itself, no problem. Failure should be located within the control valve or control parts of the valve flow.

Check the rotary solenoid proportional valve. Open after cleaning is not abnormal.

Check the rotary control valve of the flow compensation valve. Found to have been stuck spool. Deburring and cleaning out after installation. Troubleshooting.

120 UHO83-7. Turn left to walk and no sudden movements. No operator action reflects the hearing at the same time, "cracking" sound Cui Xiang, about the location in the main pump. After the test drive pump rotating components not found exception, not the pump outlet pipe vibration. Preliminary judge for the variable institutional failure. After the pump body decomposition variables, we found two variables call off a break. After the pump is always in the smallest variable position. Replacement of a new after-sales troubleshooting.

121 HD900-7. No sudden movements on the bus, but walking around normal. The four actuators on the car-free movement. As the walking machine to manipulate the mechanical manipulation. And hence independent of the main pump and a variable part. Failure should be in the pilot system. Test Pilot pump outlet pressure, the pressure is 0. Pilot pump outlet tubing removed, start the engine without oil flow pipeline, pilot pump drive shaft may fracture. Sure enough, after decomposition. After replacing new troubleshooting

123 E200B. Turn gradually slow, weak.

V. state control officers: the first found in the small engine throttle position in order to manipulate the rotation, it must be the engine throttle to increase the work unit or stroke end position rotary motion to be working. And a month ago, will be able to use the idle rotation operation.

Test on the machine, the machine all the action slower than normal. Check the pilot pump outlet pressure, only 1.1IMPa, the normal pressure of 3. 14MPa. Adjust the pilot pressure relief valve, is invalid.

Check the pilot filter found a large number of aluminum at the end, determine the pilot pump damage. Found by the decomposition of the pilot pump housing sweep chamber. Replaced with new pump and valve adjustment is correct troubleshooting. .

124 EX200-1. Suddenly turn left to walk slow Boom Stick.

After testing the pump pressure 30MPa, normal. For such a sudden, after the failure to consider the possibility of a larger body pump variable. If the pump tubing to pump failure in itself should be an exception. Decomposed body pump variables: find the ladder-shaped constant power limit adjustment piston is stuck in the stressful position, causing the pump displacement minimum.

Remove the foreign body installed for testing, the fault disappears. ,

125 PC200-5. Walking deviation.

Only found after the test machine running side of the deviation. Exchange of two main pump tube to the other side of the deviation, or variable pum, p failure in the main body. Routinely adjust the servo valve, when trying to increase the pump flow, is invalid; when trying to reduce the main pump flow is also invalid. Open the servo valve cover and found the piston within the servo valve has rust.

Cleaning rust piston and valve, the valve will move freely to the large flow regulation. Correction was successful.

126 EX200-1. Failure: the first non-sudden turn, but move the boom or bucket after bucket when rotating rod; then only turn only move when walking.

The steam machine seized at least 18,000 hours or more.

By the failure phenomenon can be seen on the pump, control valve and the rotary motor, no problem. Open the rotary brake pressure test for the 4.2MPa, is normal. Open the rotary brake pressure test for the 1.2MPa, too.

As the machine used for many years, the various components of a serious leak, can not increase the pressure. The scene only to take the enemy brake return spring to reduce force method. After the rotation by the above measures to deal with normal operations.

127 EX200-2. Turn gradually weak.

Check the rest of the test machine moves were normal. Also found three cylinders while running to the end of travel control rotary movement, the rotation speed and powerful. Check the rotation of the electromagnetic proportional control valve, that valve is stuck. Failure to eliminate cleaning after installation.

Failure Analysis: When the proportional valve spool stuck, usually hydraulic control valve stuck in the maximum position. When the oil control valve is pressure compensated to take the maximum, then pump oil into the rotary control valve at least. So turning movements slow and weak.

128 EX200-2. An action or machine movements from time to time.

Proved by the large number of field experience, the shortcomings of the model is too sensitive to system contamination. If the oil pollution or poor quality oil return filter, leading to play the oil filter back pressure is too large to be broken up. Each solenoid valve and high-speed solenoid valve stuck or damaged easily. This fall is so serious pollution caused by the hydraulic system. When no action when the dirt stuck spool: spool when the occasional shock normal activities after this action. Required under the thorough cleansing of the hydraulic system and solenoid valves. Throughout the oil and filter replacement.

129 SH200A1. Stick no sudden moves.

Stick examination revealed not only does not move when being manipulated, but manipulation of the boom when the bucket cylinder rod there is a natural sink phenomenon. This it failed the same as Example 1, except that the cylinder valve stem emperor happened to get stuck in the median,

Example 45 EX200-3. Sometimes a sudden boom can not be put down. If you lift the boom can be put down.

2 machines with this machine, as is usually caused by the boom to keep the valve stuck.

130 S430. Turn around the network suddenly slow, weak.

Suddenly turn around after inspection in addition to slow, weak, but when the machine is located in the tilted state, the car can be self-Bu slip. The remaining action is normal. Accordingly, the Department may determine the rotary motor failure.

Decomposition of the rotary motor: open the cover and found that the brake piston spring preload a large hole in the copper scrap iron, broken down further found that the motor shaft and the splined cylinder has been polished. Another rotary motor plunger components are all damaged. Finally, replace the product and cleaning system installed after the run. Normal
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