Swing Brake And Armrest Lockout Valve Manifold; Description; Maintenance - Manitowoc Grove RT765E-2 Service And Maintenance Manual

RT765E-2 SERVICE MANUAL
SWING BRAKE AND ARMREST LOCKOUT
VALVE MANIFOLD

Description

The swing brake and armrest lockout valve manifold
Figure 2-26 is located on the right side of the turntable. The
manifold contains a pressure reducing valve, a 100 mesh
filter screen in the inlet port, and two three-way, two position
solenoid valves.
The pressure reducing valve provides 250 psi (1720 kPa) for
operation of the swing brake and the foot throttle.
Each solenoid valve is held in its normally open to tank
position by a spring. When the solenoid is energized, the
plunger assembly forces the spool to shift, causing the valve
to shift. Deenergizing the solenoid causes spring pressure to
shift the spool to its normally closed position.
One solenoid valve serves as the swing brake release valve.
This normally open to tank valve, when de-energized,
prevents hydraulic oil pressure from releasing the swing
brake. When the Swing Brake Switch is in OFF, this valve
opens to allow hydraulic oil pressure to release the swing
brake.
The other three-way, two-position solenoid valve serves as
the controller armrest lockout valve. This normally open to
tank valve is de-energized when the Crane Function Switch
is in OFF, the armrest is raised, or the operator is not in the
seat. When de-energized, the valve prevents hydraulic oil
pressure from reaching the pilot circuits (the circuits the
swing, lift, telescope, and each hoist remote control valve
use to control the directional control valves). When the
Crane Function Switch is ON, this valve opens to allow
hydraulic oil pressure to all of the pilot circuits, remote control
valves, and directional control valves. This valve, when
closed, prevents accidental turntable, hoist, or boom
movement.

Maintenance

Removal
1. Tag and disconnect the electrical connectors to the

swing brake and armrest lockout valve manifold.

2. Tag and disconnect the hydraulic lines from the
manifold. Cap or plug the lines and ports.
3. Remove the capscrews, lockwashers and flatwashers
securing the manifold. Remove the manifold and two
spacer bushings.
Installation
1. Position the manifold and spacer bushings on turntable
and secure with the capscrews, flatwashers and
GROVE
lockwashers. Torque capscrews; refer to Fasteners and
Torque Values, page 1-16 for proper torque value.
2. Connect the hydraulic lines to the manifold as tagged
during removal.
3. Connect the electrical connectors to the manifold as
tagged during removal.
Function Check - Swing Brake Release Valve.
1. Position the Swing Brake Switch to OFF. Verify the
Swing Brake Engaged LED in the steering column
display goes out.
2. Swing the turntable to verify the swing brake has
released. Step on the power brake valve to stop the
turntable.
3. Position the Swing Brake Switch to ON. Verify the Swing
Brake Engaged LED in the steering column display
comes on.
4. Activate swing and ensure the turntable will not rotate,
indicating the swing brake is on.
5. Check for leaks. Make repairs as needed.
Function Check - Crane Function Valve
1. Position the Crane Function Switch to OFF.
2. Start the engine.
3. Try to telescope the boom in and out, lower and raise the
boom, hoist each hoist up and down, and swing the
turntable left and right. Verify none of these functions
work.
4. Position the Crane Function Switch to ON. Put the
armrest down, and sit in the seat.
5. Verify the following functions:
a. Telescope the boom in and out
b. Lower and raise the boom
c. Hoist each hoist up and down,
d. Swing the turntable left and right.
6. Check for leaks. Make repairs as needed.
Inlet Filter Screen Replacement
NOTE: The filter screen should be replaced every 2000
hours or if crane functions slow down.
1. Disconnect the inlet line from the "P" port on the valve
and remove the fitting from the port.
2. Remove hollow lock screw, spacer, and filter screen.
3. Install new filter screen, spacer, and hollow lock screw.
4. Install fitting in the "P" port and connect the inlet line.
Published 9-04-2014, Control # 422-08
HYDRAULIC SYSTEM
2-43
2