Komatsu Galeo PC800-8 Shop Manual page 189

10 Structure, function and maintenance standard
Operation of swing brake
1) When swing brake solenoid valve is de-ener-
gized
If the swing brake solenoid valve is de-ener-
gized, the flow of pressurized oil from the control
pump is shut off, and port B is connected to the
tank circuit.
As a result, brake piston (6) is pushed down by
brake spring (7), pushes disc (5) and plate (4)
together, and the brake is applied.
2) When swing brake solenoid valve is excited
When the swing brake solenoid valve is ener-
gized, the valve is switched, and pressurized oil
from the control valve enters port B and flows to
brake chamber a.
The pressurized oil entering chamber a over-
comes brake spring (7) and pushes brake piston
(6) up. As a result, disc (5) and plate (4) are sep-
arated and the brake is released.
PC800, 850-8
SEN00384-02
27