In the process of using the excavator, the failure of "exciting mobile arm at low speed or weak boom" occurred.
Causes:
1. Safety valve and charge valve are damaged
2. Operation valve spool does not operate normally
3. LS shuttle valve action (LS shuttle valve for right travel or bucket) is incorrect
4. Boom cylinder piston seal failure
5. Pressure compensation valve or pressure compensation valve piston malfunction
6. The PPC valve is damaged.
solution:
1. Repair or replace the safety valve and charge valve.
2. Check and adjust the operation valve spool.
3. Check and adjust the operation of the LS shuttle valve (LS shuttle valve for right travel or bucket).
4. Replace the boom cylinder piston seal.
5. Repair pressure compensation valve or pressure compensation valve piston.
6. Replace the PPC valve.
