1. Investigate the actual pressure relief condition of the oil cylinder. Use a marker to mark the cylinder piston rod orientation and record the distance that the piston rod changes per unit time. When the cylinder is tilted, the mast is close to the level; when the pressure cylinder is marked, the power head orientation can be marked. You can also listen to sounds, such as the pressure relief of a pressurized cylinder, you can usually hear the "click" sound of the power head sliding down.

2. The cylinder is exposed: the cylinder reciprocates more than five times, and investigate whether there is an oil film on the piston rod. Retract and hold the pressure of the oil cylinder, and investigate whether there is oil leakage from the orientation of the guide sleeve of the oil cylinder.

3. Balance valve, remove all the hydraulic tubing connected to the balance valve. If the oil port of the balance valve keeps dripping, it means that the balance valve is leaking. It is also possible to remove both the left and right tilt cylinder balance valve oil pipes for comparison and find problems more easily.

4. If the balance valve drains oil, it needs to be drained from the cylinder. Retract the cylinder to the limit position, remove the large cavity hydraulic tubing of the cylinder (close to the large cavity side), continue to retract the cylinder, and record the oil output status of the tubing