8-27
RT770E
UNDERCARRIAGE
8
Published 11/26/2014, Control # 447-05
GROVE
Maintenance
Troubleshooting
Table 8-4
Symptom
Probable Cause
Solution
1.
Slow or erratic operation of
o u t r i g g e r e x t e n s i o n
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.
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.
1.
Slow or erratic operation of
o u t r i g g e r e x t e n s i o n
cylinders. (continued)
i.
Damaged extension cylinder
(internal parts).
i.
Remove extension cylinder and
repair as necessary.
j.
Bent cylinder rods.
j.
Replace piston rods and seals.
k.
Excessive material on
outrigger beams.
k.
Clean outrigger beams.
l.
Binding outrigger beam.
l.
Repair or replace outrigger beam.
m.
Damaged outrigger valve.
m.
Repair or replace valve.
n.
Damaged valve coil.
n.
Replace coil.
o.
Main hydraulic pump
cavitation.
o.
Replace or tighten hose or fitting.
Refer to your Manitowoc Crane Care
Parts Manual.
p.
Partially shifted hydraulic
spool in selector valve or
manifolds.
p.
Disassemble, clean, and polish
spool and valve housing with very
fine emery cloth (water paper).
q.
Insufficient voltage for
operation of solenoid valve.
q.
Solenoids require a minimum of 9.5
volts to energize. Check outrigger
w i r i n g a n d e l e c t r i c a l c o u p l i n g
collector rings.
r.
Damaged piston seals.
r.
Replace all cylinder seals.
s.
Worn or damaged hydraulic
pump section.
s.
Repair or replace pump section.
t.
Scored cylinder barrel.
t.
Repair or replace extension cylinder.
u.
Cracked or damaged piston.
u.
Replace rod weld and all cylinder
seals.
Summary of Contents for Grove RT770E
Page 3: ...Service Maintenance Manual Grove RT770E ...
Page 4: ......
Page 40: ...INTRODUCTION RT770E SERVICE MANUAL 1 26 Published 11 26 2014 Control 447 05 THIS PAGE BLANK ...
Page 124: ...HYDRAULIC SYSTEM RT770E 2 84 Published 11 26 2014 Control 447 05 THIS PAGE BLANK ...
Page 149: ...4 5 Published 11 26 2014 Control 447 05 RT770E SERVICE MANUAL BOOM 4 GROVE FIGURE 4 2 ...
Page 150: ...BOOM RT770E SERVICE MANUAL 4 6 Published 11 26 2014 Control 447 05 FIGURE 4 2 continued ...
Page 152: ...BOOM RT770E SERVICE MANUAL 4 8 Published 11 26 2014 Control 447 05 FIGURE 4 2 continued ...
Page 154: ...BOOM RT770E SERVICE MANUAL 4 10 Published 11 26 2014 Control 447 05 FIGURE 4 2 continued ...
Page 224: ...5 24 Published 11 26 2014 Control 447 05 HOIST AND COUNTERWEIGHT RT770E This Page Blank ...
Page 276: ...POWER TRAIN RT770E 7 30 Published 11 26 2014 Control 447 05 THIS PAGE BLANK ...
Page 300: ...UNDERCARRIAGE RT770E 8 24 Published 11 26 2014 Control 447 05 FIGURE 8 28 ...
Page 348: ...LUBRICATION RT770E 9 36 Published 11 26 2014 Control 447 05 FIGURE 9 14 102 8130 2 ...
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