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GRT8100 SERVICE MANUAL HYDRAULIC SYSTEM
Published 3/26/2018, Control # 596-05
Hydraulic Pump Distribution
No. 1 Pump
The torque converter drives the No. 1 variable displacement
piston pump, which supplies oil to the following manifolds
and valves:
• Combination manifold on the carrier, which includes
valves for controlling the rear steer, axle lockout,
outriggers, and hydraulic oil cooler fan.
• Main directional control valve on the superstructure,
which includes valves for controlling the auxiliary hoist,
main hoist, boom telescope, and boom lift.
No. 2 Pump
The torque converter drives the No. 2 variable displacement
piston pump, which supplies oil to the following manifolds
and valves:
• Steer/brake/pilot supply valve on the superstructure,
which includes valves for controlling the front steering,
disc brakes, and swing brake.
• Main directional control valve on the superstructure,
which includes valves for controlling the auxiliary hoist,
main hoist, boom telescope, and boom lift.
• Telescope and telescope fill stage select/thermal
contraction valve on the superstructure.
• Compact valve on the superstructure, which includes
valves for controlling the boom lift, counterweight
removal, counterweight pin, and cab tilt.
• Main and auxiliary hoist brake release valves.
No. 3 Pump
The engine drives the No. 3 gear pump, which supplies oil to
the swing directional control valve on the superstructure.