Slow operation of the whole car: check whether the pressure of the main relief valve is abnormal, and then check whether the relief valve is blocked or worn.
The whole car does not move: it will check the pilot pressure, and the large pump pressure, and can analyze the cause of the pilot lock, pilot pump, and main pump shaft break. First see whether the circuit fault, including safety lock switch, safety lock solenoid valve, fuse; Then see whether the hydraulic oil circuit is faulty, such as checking whether the pilot pressure of the excavator is normal, whether the main relief valve is normal, and the hydraulic pump, hydraulic oil return filter and other components.
Single action failure: an action has no speed or is very slow, and other actions have normal speed or no action. First check the sealing of the shuttle valve, and then remove the shuttle valve to check whether there are scratches and wear, whether the steel ball in the memory shuttle valve is worn, check whether the steel ball can slide freely in the shuttle valve, if there is not smooth or oil leakage, it needs to be repaired or replaced.