SERV1851 02/08
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Text Reference Pilot System 311D / 312D / 314D PILOT HYDRAULIC SYSTEM
Swing Motor
Left Travel Motor
Right Travel Motor BR2
AR1 BL1
bR3
AR2
BL1
BR2
BL1 AL1
BR3
bR3
AR3
AR2 BR1
AR1
bR1
AL1
bL1
AL2
BL2
bL2
bL4
BL4
aL4
Stick 1
Main Control Valve Group Medium Pressure Circuit (if equipped)
aR3
aR1
PR
aL1
aL2
PL
aL4
aR2
bL1
bR1
Travel Levers aR1
aL1
Pilot Manifold
P
Pilot Filter
PR
Pilot Pump aL2
bR3
aR2
Left Joystick
bR2
bL4
Right Joystick
M aL4
Tank aR3
PL
bL2 P
60
PILOT SYSTEM The oil delivered from the pilot pump performs the following main functions. - Provides pilot oil pressure to the pilot control valves for implements, swing and travel to perform machine operations. - Creates pilot oil pressure to control the output flows of the main pumps. - Creates pilot oil pressure to automatically operate the control devices. The pilot circuit is classified into the following circuits and each circuit performs one of the above functions. - pilot control valve circuit
- power shift pressure system
- pressure switch circuits
- straight travel valve circuit
- swing parking brake
- boom priority
- swing priority
- automatic travel speed change
This section of the presentation will cover the pilot manifold, the implement joysticks, and the travel pilot valves.
