Forestry and Logging Equipment: Skidding Tractor (Skidder) Caterpillar

Model	Type of pump
D4H	variable displacement piston pump measures the applied load
545C grapple	variable displacement piston pump
545	Axial-piston pump
535C grapple	variable displacement piston pump
535B	Axial-piston pump
527	load sensing, variable displacement piston pump
525C grapple	variable displacement piston pump
525B	Axial-piston pump
518	Piston
515	Piston