Daewoo Solar 470LC-V, Shop Manual

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S0702190K
Page 9
Hydraulic System Troubleshooting, Testing and
Adjustment
RIGHT SWING OPERATING CIRCUIT
When the swing control lever is pushed to the
right swing position, pilot pressure from the left
side pilot valve is directed to SWING spool of
the control valve. Output flow from PUMP(R) is
goes to the swing motor.
LEFT SWING OPERATING CIRCUIT
When the swing control lever is pushed to the
left swing position, pilot pressure from the left
side pilot valve is directed to SWING spool of
the control valve moves in the opposite direction
and output flow from the PUMP(R) is goes to the
swing motor.
SWING RELIEF VALVE AND MAKE-UP VALVE
Whenever the spool is shifted to the neutral mode during swing operation, the possibility exists that surge
pressure in the circuit - caused by inertial momentum of the upper works and correspondingly reduced
pressure at the opposite motor port - could produce cavitation in the circuit. To keep that from happening, a
relief valve is installed in the swing motor and a large-capacity make-up valve is connected to the entrance
port of the hydraulic reservoir, helping maintain acceptable pressures on both sides of the circuit.
NOTE: Relief Valve Setting Pressure:
S420LC-V: 270.0 kg/cm
2
(3,840 psi)
S470LC-V: 280.0 kg/cm
2
(3,980 psi)
TRAVEL OPERATING CIRCUIT
Output flow from both halves of the pump assembly is directed to the right and left travel motors through
the right and left sides of the control valve, and the upper works center joint.
SWING MOTOR
SWING
SWING
RIGHT
PILOT
PUMP(L)
PUMP(R)
ATS0810L
Figure 8
SWING MOTOR
SWING
SWING
LEFT
PILOT
PUMP(L)
PUMP(R)
ATS0820L
Figure 9