HYDRAULIC SYSTEM
SUB-SECTION 4A
The swing brake lock is shown in its normal operating posi-
The swing brake is used to lock the swing reducer so that
tion. When the machine is not working or is shut down, the
the swing motor cannot turn, thus preventing the revolving
upper portion of the machine from turning.
swing brake lock should be placed in the locked position. In
this position, the oil in the brake chamber is allowed to
NOTE
return to tank and the brake springs set the brake.
The upper of the machine will swing freely if the
swing brake is not applied.
MAIN WINCH CIRCUIT. The main winch control valve
directs hydraulic oil from the pump to the winch motor.
The swing brake pedal is shown in the released position. In
The direction in which the valve spool is shifted will deter-
this position, oil is allowed to enter the brake chamber and
mine whether the winch will lift or lower a load. The speed
release the brake. When the operator depresses the swing
of winch operation is determined by the amount of oil
brake pedal, the oil in the brake chamber is allowed to
metered through the control valve to the winch motor.
return to tank and the brake springs set the brake.
4A-10