Grove Published 01-29-2015, Control # 512-01 2-57
TMS700E SERVICE MANUAL HYDRAULIC SYSTEM
LOWER TELESCOPE CYLINDER
Description
The boom lower telescope cylinder (Figure 2-42) has a
152 mm (6 in) bore, a 127 cm (5 in) hollow rod, and is
internally ported. Oil from the telescope control valve is
routed to the cylinder by external lines. Oil is routed to the
upper telescope cylinder by a 50.8 mm (2 in) hollow rod
inside the 127 mm (5 in) rod. Foreign material is prevented
from entering the cylinder rod during retraction by a wiper
ring in the head. O-ring seals prevent internal and external
leakage. The retracted length of the cylinder from the center
of the support block to the center of the cylinder mounting pin
is 895.9 cm (352.72 in). The cylinder has a stroke of
758.7 cm (298.69 in) which gives an extended length of
1654.6 cm (651.41 in).
The cylinder weighs 937 kg (2066 lb).
Maintenance
Disassembly
NOTE: Replace all seals and O-rings any time the cylinder
is disassembled.
1. Remove the bolts and washers securing the rod
retaining plate to the barrel.
2. Remove the bolt and washer that secures the rod
retaining plate to the inner rod end.
NOTE: Align the old seals in order of removal to facilitate
installation of new seals.
3. Using a chain wrench, unscrew the cylinder head from
the barrel. Remove the rod from the barrel and cover the
opening in the barrel to keep contaminates out of the
barrel.
4. Remove the guide lock ring from the piston to gain
access to the setscrew.
5. Remove the setscrew and unscrew the piston from the
rod.
6. Remove the remaining guide lock ring, the hydrolock
seals, and wear rings from the outside of the piston.
Remove the O-ring and two backup rings from the inside
of the piston.
7. Remove the spacer from the rod and the wear rings from
the spacer.
8. Remove the cylinder head from the rod.
9. Remove the wear rings, buffer seal assembly, deep Z
rod seal, and back-up ring from the inside of the head.
10. Remove the O-ring and backup ring from the outside of
the cylinder head.
11. Slide the inner rod out from the outer rod. The seal
retainer will slide out with the inner rod. Remove the
guide lock ring from the inner rod end.
12. Remove the seal retainer from the inner rod.
13. Remove the wear rings and deep Z rod seals from the
inside of the seal retainer.
14. Remove the O-ring and backup ring from the outside of
the seal retainer.
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 all parts with solvent that have been polished.
4. Inspect the barrel for scoring.
Assembly
NOTE: Lubricate new seals and rings with clean hydraulic
oil. Orient wear ring gaps 180° apart.
DANGER
Do not use air pressure to remove the cylinder rod. Use
only a source of controlled hydraulic oil pressure if the rod
is hard to move.
CAUTION
Do not damage the cylinder rod chrome surface.
CAUTION
Do not scratch or damage the grooved and gland
surfaces.
CAUTION
Clean all surfaces and remove all burrs and nicks before
installing new seals and ring. Replace all damaged or
worn parts.
CAUTION
Improper seal installation can cause faulty cylinder
operation.
Reference Only