Manitowoc Grove RT540E Service Maintenance Manual page 262

UNDERCARRIAGE
Functional Check
A normal periodic functional check of the entire steering
system will generally be adequate to ensure satisfactory
service.
1. Check all fittings for leakage. An accumulation of moist,
black dirt is a good indication of leakage.
2. With the engine running at idle and at full throttle, and
with the machine standing still and moving, turn the
steering wheel through the full range of travel. Note any
speed irregularities and sticky sensation. This may
indicate dirt in the fluid. If the steering wheel continues to
rotate when started and released, a condition known as
Motoring exists. This may also indicate dirty fluid in the
system.
3. Ensure the system has adequate power. If there is an
indication of hard steering, this can be caused by either
Rear Steering System
Troubleshooting
Table 8-2
Symptom
1. Rear steering inoperative.
2. Hard to steer left and right.
8-12
a reduced oil flow to the control valve or a reduced
system relief pressure. Adequate oil flow under all
conditions can best be checked by timing the full travel
of the cylinder with the steered axle unloaded and
loaded. If there is a great difference at low engine speed
and slight difference at high engine speeds this may
indicate a defective pump.
only be determined by connecting a pressure gauge
[24 MPa (3500 psi) full scale recommended] at the
accessory manifold with swing directional valve gauge
test port (GP5). With the engine running at a medium
speed, turn the steering wheel to one end of the travel
and hold the cylinders at the travel limit briefly, just long
enough to read the pressure gauge. Never hold the
system at relief pressure for more than a few seconds at
a time. The pressure gauge should indicate 17.3 MPa
(2500 psi).
Probable Cause
a. Hydraulic oil low.
b. Clogged, broken, or loose
hydraulic lines or fittings.
c. Steer cylinder locked.
d. Defective control valve.
e. Defective steer cylinder(s).
f. Lack of electrical signal
a. Hydraulic oil low.
b. Clogged or loose hydraulic
lines or fittings.
c. Defective steering
valve.
d. Defective hydraulic pump.
e. Clogged or loose hydraulic
lines or fittings.
f. Defective steer cylinder.
g. Damaged relief.
Published 4-20-2015, Control # 502-01
RT540E SERVICE MANUAL
Adequate oil pressure can
Solution
a. Refill
R e f e r
LUBRICATION.
b. Clean, tighten, or replace
lines or fittings.
c. Repair or replace cylinders.
d. Repair or replace valve.
e. Repair or replace cylinder(s).
f. Check electrical connections/
wiring
a. Refill hydraulic reservoir.
b. Clean or tighten lines or
fittings.
control c. Repair or replace valve.
d. Repair or replace pump.
e. Clean or tighten lines or
fittings.
f. Repair or replace cylinder.
g. Replace relief valve.
hydraulic reservoir.
t o S e c t i o n 9 -