Abstract: This invention relates to a slipper and swashplate cavitation erosion control and impact reduction assembly for a piston type hydraulic apparatus that includes a rotating cylinder block having at least one axially disposed bore. A piston is mounted for reciprocal movement within the bore. A fixed port plate is provided as well as a pair of different fluid pressure sources. The port plate cooperates with the rotating cylinder block to deliver alternately during two discrete and different portions of the cylinder block rotation first one of the fluid pressure sources and then the other of the fluid pressure sources to the bore and the piston. The piston has at one end thereof a slipper coupled thereto and the slipper is mounted for a sliding interface movement on a surface of a swashplate. The swashplate is nonrotatable in respect of the port plate.