Why is the overload pump of high speed punch always ringing?

    The overload oil pump of the punch has the function that the upper dead point pressure is short of filling oil, and the overload oil pump is always ringing. This shows that the hydraulic oil in the pump is mixed with air/impurities or the oil seepage occurs in the cylinder and some part of the tubing. The pressure is set up without rules, and the pressure of the punch is slightly greater than the pressure of the cylinder. Broken oil. At this time, please turn off the valve of the oil pump and turn it off several times to see if the defect can be handled. Assuming that there is oil leakage, it is necessary to remove the maintenance, check the sealing condition and replace the sealing ring.