We should be sure that this type of failure of the whole vehicle without action is mainly caused by the pump, the safety lock lever, and the pilot oil passage.
1. First determine whether there is really no movement. Turn off the engine, restart, and experiment again.
2. If there is still no action. Next, connect the pressure gauge in "F" mode to check the pump pressure and find that the left and right pump pressures are all above 330 kg, so the problem of the pump is temporarily ruled out.
3. Then, there is a piece of spring at the hydraulic safety lock lever of the machine. It is suspected whether the switch at the opening and stopping lever is out of position. Directly short-circuit the switch and make an action. There is still no response. Check the circuit and directly measure the hydraulic lock with a multimeter The two wires of the solenoid valve, the voltage is more than 25V, normal, and the resistance of the solenoid valve is also normal. After the solenoid valve was directly removed and energized, it was found that the spool of the solenoid valve was in place to eliminate the problem of the hydraulic lock solenoid valve.
4. Finally check the pilot system. The measured pilot pressure is about 35 kg, which is normal, eliminating the problem of the pilot pump. Trying the car again, there is still no movement. At this time, the pilot line is suspected, and the pilot line of the bucket control valve on the main control valve is directly disassembled, and the bucket arm is moved, and no hydraulic oil flows out. It is determined that the pilot line is a problem. The following work is to check the pilot oil path from the pilot pump to the next section, and it is found that a pilot oil pipe behind the pilot multi-way valve is blocked. After the dredge, everything is normal.
