Starting difficulties may be caused by the following reasons: Insufficient system pressure cannot overcome static friction. Check the pressure setting and the status of the axial piston pump. The internal parts of the motor, such as the plunger or the swash plate, are stuck. This is mostly caused by insufficient lubrication or oil contamination after long-term parking. You can try to manually turn the motor and replace the clean oil. The oil temperature is too low, resulting in too high viscosity, which increases the starting torque requirement. The hydraulic oil should be preheated to the operating temperature range. The variable mechanism in the minimum displacement position will also cause starting difficulties. It needs to be adjusted to the appropriate position. For motors that have been out of service for a long time, the drain port should be filled with clean oil before starting to remove the internal air.