Excavator Hydraulic Pump Kit Swash Plate for Rexroth A10VS063 R902429370 Excavator Parts Used in excavator main pumps, the swash plate is a vital internal component. It stays still while the cylinder block rotates, and piston shoes glide over its surface. Functions Piston shoes rest against the swash‑plate face. When the cylinder block rotates pistons, the slanted swash plate turns rotary movement into pistons’ back‑and‑forth movement for oil intake and pressurized oil output