SERV1851 02/08
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311D / 312D / 314D HYDRAULIC SYSTEM
Swing Motor
Left Travel Motor
Text Reference Main Hydraulic Pumps
MAIN HYDRAULIC PUMPS AND CONTROLS
Right Travel Motor BR2
AR1 BL1
bR3
AR2
BL1
BR2
BL1 AL1
BR3
AR3
bR3
AR2 BR1
AR1
bR1
AL1
bL1
AL2
BL2
bL2
bL4
BL4
aL4
Main Control Valve Group Medium Pressure Circuit (If Equipped)
aR3
aR1
PR
aL1
PL
aL4
aL2
aR2
bL1
bR1
Travel Levers aR1
aL1
Pilot Manifold Pilot Filter Main Hydraulic Pumps
aR2
Left Joystick
Pilot Pump
aL2
bR3
bR2
bL4
Right Joystick
Medium Pressure Pump (If equipped)
aL4
Tank aR3
bL2
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MAIN HYDRAULIC PUMPS AND CONTROLS This section of the presentation will cover the main hydraulic pumps and pump controls for the 311D/312D/314D Hydraulic Excavators. The main hydraulic pumps are the same as the "C" series machines. The main pump group consists of a variable displacement piston drive pump and an idler pump. The drive pump and the idler pump are contained in an integral housing. The drive pump and the idler pump are identical in construction and operation. The pumps are sometimes referred to as S.B.S. (side by side) pumps The main difference between all of the pumps is the maximum pump flow for each model. Both the drive pump and the idler pump have individual pump control valves to control the pump flow.
