What are the precautions for repairing the hydraulic pump of a 400-ton hydraulic press?

What are the precautions for repairing the hydraulic pump of a 400-ton hydraulic press?

1. Check the internal leakage of the hydraulic cylinder of the 400-ton hydraulic press:

A simple method is to lift the moving arm to see if it has obvious free fall. If the fall is obvious, please remove the gas cylinder and check whether the seal ring should be replaced if it is found to be worn.

2. Check the control valve of the 400-ton hydraulic press:

First, clean the safety valve of the hydraulic press and check whether the valve core is worn. If worn, it should be replaced. If there is no change after installing the safety valve, please check the wear of the valve stem of the four-column press control valve. The gap limit is usually 0.06mm. If the wear is severe, it should be replaced.

3. Measure the pressure of the hydraulic pump of the 400-ton hydraulic press:

If the pressure is low, adjust it. If the pressure is still not adjusted, it indicates that the hydraulic pump of the four-column press is severely worn.