SERV1851 02/08
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Text Reference Swing System Swing Motor
SWING SYSTEM FULL SWING LEFT
Anti-reaction Valves
Implement Pressure Switch
Stick 1 Valve
Swing Valve
Travel Pressure Switch
To Travel Valve From Idler Pump To Main Control Valve To Tank
Swing/Stick Pilot Valve
Swing Brake Solenoid
To Stick Regen Valve To Boom 2 Valve Swing Priority Valve
From Straight Travel Valve
From Pilot Pump Slow Return Check Valve
Pilot Manifold
145
Swing System Operation When the swing joystick is fully shifted, pilot oil from the swing joystick flows to the swing control valve to shift the control spool. The control valve shifts and blocks the oil in the center passage from flowing to the idler pump. The idler pump fully upstrokes. Also, when the swing control valve shifts, pilot oil from the pilot manifold is blocked from flowing through the pilot logic network to the tank. The increased pilot pressure closes the implement pressure switch. The Machine ECM senses the switch is closed and energizes the swing brake solenoid. The swing brake solenoid directs pilot oil to release the swing brake. The load check valve unseats and supply oil from the pump is directed to the swing motor. The swing relief cushions the start of the swing motor. Return oil from the motor flows past the swing control valve to the tank.
