Published 4-20-2015, Control # 502-01 8-27
RT540E SERVICE MANUAL UNDERCARRIAGE
PARK BRAKE VALVE
Description
The range shift/parking brake valve controls the flow of oil to
the parking brake, hi-low range and axle disconnect
actuators by the use of two solenoid valves. The valve is
located on the center of the frame. Pressure is supplied to
the valve from the transmission charge pump.
The parking brake solenoid valve is a two position three-way
valve. In its de-energized position, the inlet port is blocked
and the parking brake actuator is drained to the reservoir.
When the solenoid is energized, the reservoir port is blocked
and pressurized oil is directed to the actuator, engaging the
parking brake.
The range shift solenoid valve is a two position four-way
valve. In its de-energized position, pressurized oil flows to
the “B” port of the range shift actuator, while the “A” port is
drained to the reservoir along with the axle disconnect
actuator for two wheel drive/high range. When the solenoid
is energized, pressurized oil is directed to the “A” port of the
range shift actuator and the axle disconnect actuator while
port “B” of the range shift actuator is drained to the reservoir
for four wheel drive/low range.
Removal
1. Tag and disconnect the electrical connectors to the
valve.
2. Tag and disconnect the hydraulic hoses from the valve.
Cap or plug the lines and ports.
3. Remove the capscrews, lockwashers, flatwashers and
nuts securing the valve to the frame. Remove the valve.
Installation
1. Secure the valve to the frame with the nuts, flatwashers,
lockwashers and capscrews. Torque the capscrews 25
to 27 Nm (18 to 20 lb-ft).
2. Connect the hydraulic hoses to the ports on the valve as
tagged during removal.
3. Connect the electrical connectors to the valve as tagged
during removal.
Functional Tests
1. Start and idle engine.
2. With units on outriggers, check for proper two/four wheel
operation.
NOTE: For further information on the park brake valve,
refer to Section 2 - HYDRAULIC and PRESSURE
SETTINGS.
OUTRIGGERS
Outrigger Circuit
The outrigger circuit consists of four extension cylinders, four
jack cylinders, an integrated outrigger/rear steer valve, front
and rear outrigger control manifolds, pilot operated check
valves and four Outrigger Monitoring System (OMS)
(Optional—Standard in North America) string
potentiometers. The front two extension cylinders are
mounted in the front outrigger beams and the rear two
extension cylinders are mounted in the rear outrigger beams.
The front and rear outrigger beams are mounted in their
respective outrigger boxes; in turn a jack cylinder is mounted
on the end of each outrigger beam. The integrated outrigger/
rear steer valve is mounted on the front face of the carrier
frame front cross member. The front and rear outrigger
control manifolds are mounted on the inside center of their
respective outrigger box. An OMS string potentiometer (if
equipped) is mounted inside each outrigger box. The
potentiometer is connected by a cable to the outrigger beam
to monitor the beam’s horizontal position—fully retracted,
mid-extend, or full extended.
The outrigger selector controls are located in the cab on the
CCS display or jog dial. Both the integrated outrigger valve
and the manifold solenoid valves are electrically actuated
from these controls. The solenoid switches must be
depressed and held to actuate the solenoid valves. The
integrated outrigger valve switch is spring loaded to the off
position. The console is placarded with switch positions.
A sight bubble level is mounted on the right side of the cab.
The sight bubble level provides the operator with a visual
indication of crane level attitude.
Theory of Operation
NOTE: Refer to Section 3 - OPERATING CONTROLS and
PROCEDURES in the Operator Manual for
operation of the outrigger switches.
Reference Only
To Next Page
Loading...
Need help?
General
