Hydraulic Remote Control Valve; Description; Maintenance - Manitowoc Grove RT770E Service Maintenance Manual

HYDRAULIC SYSTEM

HYDRAULIC REMOTE CONTROL VALVE

Description

The crane has four single axis hydraulic remote control
valves (Figure 2-21). Each valve has a control lever for the
operator's use.
The four hydraulic remote control valves are single function
type valves. Moving the control lever forward or back
operates the selected function. Two valves are located in
each armrest. The valves in the right armrest control the
main hoist and boom lift. The valves in the left armrest
control swing and telescope.
NOTE: If the crane has an optional auxiliary hoist, the
auxiliary hoist function replaces the telescope
function on the control lever on the left armrest.
The telescope function is controlled by a pedal
operated single function control valve. The pedal is
on the cab floor. The control valve is mounted on
the left rear underside of the cab and is connected
to the pedal by linkage.
When the armrests are up, the crane function switch is off, or
the operator leaves his seat, the controller lockout valve is
de-energized and the functions are disabled.
Dual Axis Controllers (CE Units)
The two hydraulic remote control valves Figure 2-22 are dual
function joystick type valves. One valve is located in each
armrest. The valve in the right armrest controls the main
hoist and boom lift. Moving the control lever straight forward
or back operates the main hoist function. Pushing the control
lever to either side operates boom lift. Positioning the lever in
a diagonal direction operates both functions simultaneously.
The valve in the left armrest controls swing and telescope.
Pushing the control lever straight forward or back controls
the telescope function. Pushing the control lever to either
side operates swing. Positioning the lever diagonally
operates both functions simultaneously.
2-38
NOTE:

Maintenance

Armrest Control Valve Removal
1.
2.
3.
Armrest Control Valve Installation
1.
2.
3.
Armrest Control Valve Functional Check
1.
2.
3.
Published 11/26/2014, Control # 447-05
If the crane is equipped with an optional auxiliary
hoist, the auxiliary hoist function replaces the
telescope function on the control lever of the left
armrest and the telescope function is controlled by
a pedal operated single function control valve
Figure 2-23. The pedal is located on the left side of
the cab floor. The control valve is mounted beneath
the cab and is connected to the pedal by linkage.
Gain access to the base of the control valve by raising
the armrest and removing the plastic cover screwed
onto the bottom of the armrest.
Tag and disconnect the hydraulic lines to the control
valve. Cap or plug the lines and ports.
Remove the bolts securing the control valve to the
armrest. Remove the control valve.
Place the valve on the armrest. Secure the valve to the
armrest with the attaching bolts.
Connect the hydraulic lines to the valve as tagged during
removal.
Install the plastic cover on the bottom of the armrest.
Secure it with screws, washers and nuts.
Start the engine and run it at normal speed.
Move each control lever to operate the function
controlled by the corresponding control valve. Verify
proper operation of the hoist motor, swing motor, lift
cylinder, and telescope cylinder (or auxiliary hoist).
Check valve and lines for leakage. Make repairs as
needed.
RT770E