8-24 Published 08-25-09, Control # 077-04
UNDERCARRIAGE RT9130E SERVICE MANUAL
OUTRIGGER CIRCUIT
Description
The outrigger circuit consists of four extension cylinders, four
stabilizer cylinders, an integrated outrigger/rear steer valve,
front and rear outrigger control manifolds, and pilot operated
check valves. 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 on their respective
outrigger boxes; in turn the stabilizer cylinders are mounted
on the end of each outrigger beam. The integrated outrigger/
rear steer valve is mounted on the rear 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.
The outrigger selector controls are located in the cab on the
front console. Both the integrated outrigger valve and the
manifold solenoid valves are electrically actuated from these
controls. The solenoid switches must be held depressed to
actuate the solenoid valve. 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 left side of the cab by
the door latch plate. The sight bubble level provides the
operator with a visual indication of crane level attitude.
Theory Of Operation
The appropriate EXTENSION/STABILIZER switch must be
depressed before the OUTRIGGER Extend/Retract switch is
depressed. Depressing one of the outrigger selector
switches causes that solenoid valve to open. As the
OUTRIGGER switch is moved, the integrated outrigger valve
spool shifts allowing flow to either the extend or retract line
as applicable. If the OUTRIGGER switch is in the Extend
position, the flow continues through the open solenoid valve
to the piston side of the cylinder. If the stabilizer is to be
extended, the flow first unseats the cylinder check valve then
extends the cylinder. The oil from the rod end flows through
the integrated outrigger valve, and then to the reservoir.
When the OUTRIGGER switch is in the Retract position, the
flow through the selector valve is directed to the rod side of
the cylinder. The oil in the piston side flows through the open
solenoid back to the integrated outrigger valve. If a stabilizer
cylinder is to be retracted, then pilot pressure from the
pressurized retract line unseats the cylinder check valve
allowing oil to flow from the piston side through the open
solenoid valve to the integrated outrigger valve. The
integrated outrigger valve directs the flow to the reservoir.
The integrated outrigger/rear steer valve contains three relief
valves. The main relief is set at 24,133 kPa (3500 psi).
Thermal relief protection is provided on the extend side by a
27,580 kPa (4000 psi) relief valve and the retract side by a
27,580 kPa (4000 psi) relief valve.
Maintenance
Table 8-4
Troubleshooting
Symptom Probable Cause Solution
1. Slow or erratic operation of
outrigger extension cylinders.
a. Damaged relief valve. a. Remove relief valve; clean or
replace.
b. Low hydraulic oil. b. Check system for leaks. Make
repairs as needed. Fill
reservoir. Refer to Section 9 -
Lubrication.
c. Sticking solenoid valve spool. c. Repair or replace valve spool.
d. Improper ground to base of
solenoid.
d. Ground properly.
e. Directional selector switch
sticking.
e. Clean or replace switch.
f. Collector ring dirty or glazed. f. Clean and deglaze collector
ring.
g. Damaged wiring to solenoid. g. Replace wiring.
h. Weak brush springs on
collector ring.
h. Replace brush springs. Refer
to your Manitowoc Crane
Care Parts Manual.
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