When the axial piston type hydraulic pump is used in an actual site, a leakage occurs in the rotating parts due to a sudden change in pressure and a change in flow rate, the balance between the swash plate and the hydrostatic bearing of the piston shoe is broken, It causes mechanical wear, resulting in efficiency reduction, which is the main performance as a pump. In order to prevent this, a solenoid valve of the pump itself is mounted to protect against overload. In this study, by replicating conditions such as flow rate and pressure when the pump is operated under actual site conditions, proceed with the life test of 750 hours, observe the performance deterioration before and after the life test, We confirmed the transition of the applied field mode of the piston pump and the change of the pump efficiency and compared it.