Manitowoc Grove RT880E User Manual

Grove Published 11-10-2014, Control # 524-00 2-77
RT880E SERVICE MANUAL HYDRAULIC SYSTEM
2
TROMBONE TELESCOPE CYLINDER
Description
The boom trombone telescope cylinder (lower telescope
cylinder) has a 7.0 in (17.7 cm) bore, a 6 in (15.2 cm) hollow
rod and is internally ported. Oil from the telescope control
valve is routed to the cylinder by external lines. Foreign
material is prevented from entering the cylinder rod during
retraction by a wiper seal in the head. O-ring seals prevent
internal and external leakage (Figure 2-43).
The retracted length of the telescope cylinder is 389.5 in
(1014.8 cm). The cylinder has a stroke of 347.0 in (8815 cm)
which gives an extended length of 746.5 in (1896 cm).
The cylinder weighs approximately 2908 lb (1319 kg) wet.
Maintenance
Disassembly
NOTE: Any maintenance requiring disassembly of the cyl-
inder should include replacement of all cylinder
seals and O-rings.
1. Remove the bolts and washers securing the rod retain-
ing plate to the barrel.
2. Remove the bolts and washers that secures the rod
retaining plate to the inner rod end.
3. Using a chain wrench, unscrew the cylinder head from
the barrel.
4. Remove the cylinder rod assembly from the cylinder bar-
rel and cover the barrel to avoid contamination.
NOTE: Aligning discarded seals and rings in the order of
disassembly will facilitate installation of new seals
and rings.
5. Remove the guide lock ring to gain access to the set-
screw securing the piston to the outer cylinder rod.
6. Remove the setscrew and unscrew the piston from the
cylinder rod.
7. Remove the hydrolock seals and wear rings from the
outside of the piston and the O-ring and backup ring
from the inside of the piston.
8. Remove the spacer from the rod and remove the wear
ring from the spacer.
9. Remove the cylinder head from the outer rod.
10. Remove the O-ring and backup rings from the outside of
the head and the wear rings, buffer seal, deep Z rod
seal, backup ring and the wiper ring from the inside of
the head.
11. Using a spanner wrench, unscrew the inner rod from the
outer cylinder rod and cover the opening to avoid con-
tamination. The seal retainer will slide out from the inner
rod.
12. Remove the polyseal ring from the inner rod end.
13. Remove the O-ring and backup rings from the outside of
the inner rod.
14. Remove the wear rings and rod seals from the inside of
the seal retainer.
15. Remove the O-ring and backup rings from the outside of
the seal retainer.
16. If necessary, remove the holding valve from the inner
cylinder rod and from the cylinder barrel.
Inspection
1. Clean all parts with solvent and dry with compressed air.
Inspect for damaged or worn parts and replace as
required.
2. Stone out minor blemishes and polish with fine crocus
cloth.
3. Clean with solvent and dry with compressed air any
parts that have been stoned and polished.
WARNING
Do not use air pressure to remove the cylinder rod
assembly. Use only a source of controlled hydraulic oil
pressure if the rod is hard to remove.
CAUTION
Exercise extreme care when handling or setting down the
cylinder rod. Do not damage the chrome surface.
CAUTION
When removing seals and rings, avoid scratching
grooved and gland surfaces.
CAUTION
Do not use air pressure to remove the cylinder rod
assembly. Use only a source of controlled hydraulic oil
pressure if the rod is hard to remove.
Exercise extreme care when handling or setting down the
cylinder rod. Do not damage the chrome surface.
CAUTION
Clean all surfaces and remove all burrs and nicks before
installing new seals and rings. Replace all damaged or
worn parts.

Manitowoc Grove RT880E Specifications

General

Brand	Manitowoc
Model	Grove RT880E
Category	Construction Equipment
Language	English