Maintenance - Manitowoc Grove RT770E Service Maintenance Manual

RT770E

MAINTENANCE

Table 6-1: Troubleshooting
Symptom
1. Boom swing
operation erratic in
either direction.
GROVE
Probable Cause
a. Damaged relief valve.
b. Swing brake dragging (not releasing
properly).
c. Low engine rpm.
d. Low hydraulic oil.
e. Improper movement of control to
neutral.
f. Insufficient lubricant on swing bearing.
g. Crane not level.
h. Damaged swing motor.
i. Excessive overload.
j. Restricted or partly clogged hydraulic
hose or fittings.
k. Pump cavitation in swing section.
l. Improperly torqued turntable bolts.
m. Excessive preload on upper and lower
pinion shaft bearing.
n. Improperly torqued
attachment bolts.
o. Malfunction of the swing box.
p. Worn or damaged pump.
q. Damaged swing directional control
valve.
r. Damaged swing pinion.
s. Damaged turntable bearing.
t. Controller settings
u. Electrical connection
Published 11/26/2014, Control # 447-05
a. Replace relief valve.
b. Readjust and/or replace necessary
parts.
c. Increase engine rpm to obtain smooth
swing operation.
d. Check system for leaks. Make repairs
as needed. Fill reservoir.
e. Feather controls to neutral to maintain
smooth stopping action.
f. Lubricate bearing properly. Refer to
Lubrication, page 9-1.
g. Level crane using outriggers.
h. Repair or replace swing motor.
i. Reduce load. Refer to load capacity
chart.
j. Replace hose or fittings. Refer to the
Manitowoc Crane Care Parts Manual.
k. Tighten suction hose or replace any
damaged fitting. Check hydraulic tank
level.
l. Torque turntable bolts evenly.
m. Adjust as necessary.
swing motor n. Torque swing motor attachment bolts.
o. Remove
necessary repairs.
p. Repair or replace damaged pump.
q. Repair or replace swing directional
control valve.
r. Replace pinion.
s. Replace turntable bearing.
t. Check settings
u. Inspect wiring and connections
SWING SYSTEM
Solution
swing box and make
6-3
6