Komatsu 200-7 excavator middle arm cylinder recycling card

Excavator failure phenomenon:

After 8000 hours of Komatsu 200-7 excavator changed the oil seal, it was found that when the wall cylinder of the excavator was finished, it would be stuck. What is the problem?

Komatsu 200-7 excavator middle arm cylinder recycling card failure possible analysis:

1 It may be that the holding valve is slightly issued, or the regeneration check valve is issued.

2 Into the air.

3 buffer sleeve problem.

Cause Analysis.

Komatsu 200-7 excavator smashed the machine, the action is slow, and the solenoid valve has no effect. What is the problem?

1 The flow is too large, causing the machine to crash, and the slow movement is caused by poor flow adjustment.

2 Is the solenoid valve replaced with Komatsu original parts? It is recommended to use a pressure gauge to measure some pressure parameters on the pump. First measure the output pressure of the PC-EPC (test condition P mode, automatic deceleration canceled, in the middle of the handle) At the highest speed, the measured pressure value is close to 0 kg; the lowest measured pressure should be close to 30 kg). If there is something wrong, it is the problem of the solenoid valve. (The test interface has five plugs on the middle valve body. The first two things are the front and rear pump PC-EPC.)

3 If it is determined that the PC-EPC is good, measure the pressure at the big end of the servo piston, that is, adjust the PC valve. https://jnjmzm.wixsite.com/sdjygcjx