1、 Komatsu PC200-5, suddenly the whole vehicle is slow, and the pump control computer board displays fault code: 17. It indicates that there is a problem with the engine speed. Check the speed sensor and its harness. It is found that one wire of the sensor is disconnected and normal after connection.
2、 Komatsu PC200-5 suddenly disappeared within a few minutes of turning and right walking. It is found that the oil outlet pipe of the front pump vibrates strongly during the test run. Check that there is a large amount of copper and iron dust in the oil return filter element of the oil tank. Copper and iron particles also appear in the oil drain of the front pump housing. The front pump is seriously damaged.
3、 Komatsu PC200-5 is a second mobile phone, which has been used for 3 years. After purchasing the machine, it was found that the bucket rod and lifting boom were slow during operation, and others were normal. After inspection, the half flow valve of the tie-in stick was artificially changed and worked normally after the original system was restored.
4、 Komatsu PC200-5, crawler walking is weak, and there is no low gear for walking. After replacing the seal of the central swivel, the fault remains. Check the travel speed solenoid valve and find that the valve core is stuck due to dirt in the oil. Normal after cleaning.
5、 Komatsu PC200-5, suddenly no rotation, other actions are normal.
Check: start the engine, loosen the swing brake control oil pipe, and find that there is no pressure oil in the oil pipe. It indicates that the outlet pressure of the self swing braking solenoid valve is abnormal. There may be two reasons: first, the solenoid valve core may be stuck in the closed position and the pilot oil cannot pass through; second, the solenoid valve coil may be open and the valve core cannot be opened. Measure the coil resistance with a multimeter. The resistance is 0 and the normal resistance value should be 15.5. The solenoid valve is normal after replacement.
6、 Komatsu PC200-5 has great impact at the beginning and end of turning and right walking. During the test run, it is found that the intermediate operation process is normal and other actions are normal except for the rotation and right travel starting and braking.
7、 Komatsu PC200-5, walking deviation.
After the test run, only one side of the machine was found to deviate. After exchanging two main pump pipes, it is changed to deviation on the other side, and the fault is the main pump or its variable mechanism. Adjust the servo valve according to the routine. When trying to increase the pump flow, it is invalid; It is also ineffective when trying to reduce the flow of the main pump. Open the upper cover of the servo valve and find that the piston in the servo valve has been rusted.
