Forestry and Logging Equipment: Skidding Tractor (Skidder) Caterpillar

Model	Type of pump	Overflow valve pressure	Pump flow rate
D4H	variable displacement piston pump measures the applied load	18615.8 kPa - 2700 lb / sq. inch	94.6 l/min - 25 gal/min
545C grapple	variable displacement piston pump	20994.5 kPa - 3045 lb / sq. inch	189.3 l/min - 50 gal/min
545	Axial-piston pump
535C grapple	variable displacement piston pump	20994.5 kPa - 3045 lb / sq. inch	174.1 l/min - 46 gal/min
535B	Axial-piston pump
527	load sensing, variable displacement piston pump	20690 kPa - 3000.8 lb / sq. inch	111 l/min - 29.3 gal/min
525C grapple	variable displacement piston pump	20994.5 kPa - 3045 lb / sq. inch	174.1 l/min - 46 gal/min
525B	Axial-piston pump
518	Piston	20684.3 kPa - 3000 lb / sq. inch	172.2 l/min - 45.5 gal/min
515	Piston	20684.3 kPa - 3000 lb / sq. inch	172.2 l/min - 45.5 gal/min