Excavator Pump Parts Rexroth A10VSO63 Piston Shoe R902418043 Set of 9 pcs Spare Parts Power Transfer and Automatic Angle Adaptation Pistons reciprocate linearly within the cylinder block while the swash plate stays fixedly tilted. Linked via spherical hinge, the piston shoe swings freely matching swash plate inclination and transmits axial piston thrust steadily to the swash plate. If piston shoes are removed, piston ball heads touch the swash plate only at discrete points,