During the use of Caterpillar excavator, the fault of "excavator boom low speed or boom weakness" occurs.
Causes:
1. The safety valve and oil makeup valve are damaged
2. The action of operating valve slide valve is abnormal
3. LS shuttle valve action (LS shuttle valve for right travel or bucket) is incorrect
4. The piston seal of boom cylinder fails
5. The pressure compensation valve or piston of the pressure compensation valve acts poorly
6. The PPC valve is damaged.
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Solution:
1. Repair or replace the safety valve and oil makeup valve.
2. Check and adjust the slide valve of the operating valve.
3. Check and adjust the action of LS shuttle valve (LS shuttle valve for right travel or bucket).
4. Replace the piston seal of boom cylinder.
5. Repair the pressure compensation valve or pressure compensation valve piston.
6. Replace PPC valve.
