Excavator PC3000 / PC4000 Hydraulic Swing Motor Part Number 95930840 / 89659040 Common Faults Insufficient swing torque, weak swing and difficult start-up of large excavator Unstable swing speed, jerky swing motion and heavy shock during start & stop Abnormal noise of swing motor with housing vibration Oil leakage on motor housing, damaged oil seals and gaskets Wear of internal valve plate and plunger, excessive operating temperature Loss of swing holding pressure, upper