All actions of the excavator cannot be moved
main cause:
(1) Serious shortage of hydraulic oil
(2) The security lock cannot be released
(3) Diagnosis process of pilot pump failure, coupling damage and pump shaft fracture:
Step 1: check whether the hydraulic oil level is normal and supplement the hydraulic oil if necessary.
Step 2: check whether the safety lock fuse is intact. If it is intact, use a multimeter to check whether the solenoid valve end 9# line is powered on. If it is not powered on, check whether the travel switch works normally. If it is normal, it is a line fault. Find the open circuit and repair it; If the solenoid valve end 9# line is energized, remove the solenoid valve and conduct on-off test. If the valve core cannot act, the valve core is stuck or the solenoid coil is damaged. Repair or replace it.
Step 3: check whether the pilot pressure at the outlet of the safety locking solenoid valve is normal. If it is abnormal, check the outlet pressure of the pilot pump. If the pressure is normal, it indicates that the pilot solenoid valve core leaks seriously and needs to be repaired or replaced; If the outlet pressure of the pilot pump is abnormal, the pilot pump overflow valve is faulty or the pilot gear pump is seriously worn, which should be repaired or replaced; If the pilot pump outlet pressure is 0.
The excavator engine works normally, and each action of the working device slows down
main cause:
(1) Insufficient and deteriorated hydraulic oil
(2) Poor pump suction and oil return
(3) Low pilot pressure
(4) Poor pilot oil circuit
(5) Low overflow pressure of main valve
（6） Diagnosis process of serious pump wear: Step 1: check whether the hydraulic oil is deteriorated and the brand is correct. If it does not meet the requirements, replace it. Step 2: check whether the oil suction and return circuits are unblocked. If not, clean or replace them. Measure the pressure of the two main pumps. If the results are zero, it means that the engine output power is not supplied to the hydraulic pump. In this case, check the coupling and the pump shaft of the main pump Whether it is broken. If the coupling or main pump shaft is broken, replace it in time.
Step 3: check whether the pilot oil pressure is normal. If it is too low, adjust it to the normal value.
Step 4: check whether the pilot oil circuit is unblocked. If not, clean or replace it.
Step 5: check whether the overflow pressure of the main valve is normal. If it is too low, adjust it to the normal value.
Step 6: check whether the volumetric efficiency of the hydraulic pump decreases due to wear. If the pump is worn, replace the hydraulic pump.
