Grove RT9130E - Description; Disassembly; Dual Rod Telescope Cylinder; Maintenance

Published 08-25-09, Control # 077-04 2-67
RT9130E SERVICE MANUAL HYDRAULIC SYSTEM
2
GROVE
DUAL ROD TELESCOPE CYLINDER
Description
The boom dual rod telescope cylinder (upper telescope
cylinder) (Figure 2-39) has a 235 mm (9.25 in) bore. The
cylinder is internally ported (rod 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.
The retracted length of the telescope cylinder is 11005 mm
(433.25 in). The cylinder incorporates two cylinder rods,
therefore each rod has a separate stroke. Each rod has a
stroke of 8966 mm (353 in) which provides a combined
overall stroke of 17932 mm (706 in). This gives the cylinder
an overall extended length of 28931 mm (1139 in) from the
end of the cylinder barrel to the center of the attachment
fittings on the cylinder rod.
The cylinder weighs approximately 1971 kg (4345 pounds)
wet.
Maintenance
Disassembly
NOTE: Any maintenance requiring disassembly of the
cylinder should include replacement of all cylinder
seals and o-rings.
1. Using a spanner wrench, unscrew the outer cylinder
head from the cylinder barrel.
2. Remove the cylinder rod assembly from the cylinder
barrel 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.
3. Remove the hydrolock piston seal to gain access to the
setscrew securing the piston to the outer cylinder rod.
4. Remove the setscrew and unscrew the piston from the
cylinder rod.
5. Remove the remaining hydrolock seal from the outside
of the piston and the o-ring and two backup rings from
the inside of the piston.
6. Remove the spacer from the rod and remove the wear
ring from the spacer.
7. Remove the cylinder head from the outer rod.
8. Remove the o-ring and backup ring from the outside of
the head and the wear rings, buffer seal, deep Z rod
seal, and the wiper ring from the inside of the head.
9. Using a spanner wrench, unscrew the inner cylinder
head from the outer cylinder rod.
10. Remove the inner cylinder rod assembly from the outer
cylinder rod and cover the opening to avoid
contamination.
11. Remove the hydrolock piston seal to gain access to the
setscrew securing the piston to the inner cylinder rod.
12. Remove the setscrew and unscrew the piston from the
cylinder rod.
13. Remove the remaining hydrolock seal from the outside
of the piston and the o-ring and two backup rings from
the cylinder rod
14. Remove the spacer from the rod and remove the wear
ring from the spacer.
15. Remove the cylinder head from the inner rod.
CAUTION
Do not retract the cylinder completely if it is not attached
to the boom. Maintain a spacer that is split or hinged 6.88”
long to prevent cylinder from retracting completely.
DANGER
Do not use air pressure to remove the rod. Use only a
source of controlled hydraulic oil pressure if the rod is
hard to move.
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.
DANGER
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 move.
CAUTION
Exercise extreme care when handling or setting down the
cylinder rod. Do not damage the chrome surface.