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BOOM
RT770E SERVICE MANUAL
4-40
Published 11/26/2014, Control # 447-05
Removal And Installation
Removal and installation of the telescope cylinder from the
boom is described under disassembly and assembly of the
boom. Refer to
Disassembly And Assembly
Disassembly and assembly procedures of the telescope
control valve and cylinder are provided in
3.
Telescope
cylinder will not
extend.
a.
Low hydraulic oil level.
a.
Check system for leaks. Make repairs as
needed. Fill reservoir.
b.
Relief valve malfunctioning.
b.
Repair or replace relief valve.
c.
Excessive load.
c.
Reduce load.
d.
Clogged hose and fittings.
d.
Replace hose or fittings. (Refer to
Manitowoc Crane Care Parts Manual).
e.
Broken valve spool.
e.
Replace valve.
f.
Damaged piston seals.
f.
Replace all cylinder seals.
g.
Damaged piston(s).
g.
Replace piston(s) and all cylinder seals.
h.
Bent boom section(s).
h.
Replace damaged boom section(s).
i.
Broken hydraulic pump coupling.
i.
Replace broken hydraulic pump coupling.
j.
Worn or damaged hydraulic pump
section.
j.
Repair or replace pump section.
4.
Telescope
cylinder will not
retract.
a.
Low hydraulic oil level.
a.
Check system for leaks. Make repairs as
needed. Fill reservoir.
b.
Relief valve damaged.
b.
Repair or replace relief valve.
c.
Excessive load.
c.
Reduce load. (Refer to load chart).
d.
Inoperative check valve.
d.
Replace check valve.
e.
Clogged hose and fittings.
e.
Replace hose or fittings. (Refer to
Manitowoc Crane Care Parts Manual).
f.
Broken valve spool.
f.
Replace valve section.
g.
Broken piston(s).
g.
Replace piston(s) and all cylinder seals.
h.
Damaged piston seals.
h.
Replace all cylinder seals.
i.
Bent boom section(s).
i.
Replace damaged boom section(s).
j.
Broken hydraulic pump coupling.
j.
Replace broken hydraulic pump coupling.
k.
Worn or damaged hydraulic pump.
k.
Repair or replace pump.
l.
Broken hydraulic pump shaft.
l.
Replace pump shaft.
SYMPTOM
PROBABLE CAUSE
SOLUTION
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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