Excavator Parts AP2D36 Swash Plate AP2D36 Hydraulic Pump Parts The swash plate is a core inner part for excavator main pumps. It does not rotate with the cylinder block. Instead, piston shoes slide along its surface. Functions Piston shoes press to the swash‑plate face. As the cylinder block rotates pistons, the tilted swash plate converts rotation into pistons’ reciprocating movement for oil suction and pressure delivery. Swash‑plate tilt controls pump displacement. Larger