Upper Telescope Cylinder; Maintenance; Description - Manitowoc Grove TMS800E Service And Maintenance Manual

HYDRAULIC SYSTEM

UPPER TELESCOPE CYLINDER

Description

The upper boom telescope cylinder (see Figure 2-45) has a
16.5 cm (6.50 in) bore and is internally ported (rod ported).
Oil from the telescope control valve is routed to the cylinder
by the lower cylinder. Foreign material is prevented from
entering the cylinder during rod retraction by a wiper ring in
the head retaining ring and O-ring seals prevent internal and
external leakage. The retracted length of the telescope
cylinder is 1013.5 cm (399.02 in) and the extended length is
1896.3 cm (746.58 in) from the end of the barrel to the center
of the cylinder block.
The cylinder weighs 840 kg (1852 lb).

Maintenance

Disassembly
NOTE: Replace all cylinder seals and O-rings with new
ones anytime the cylinder is disassembled.
1. Using a chain wrench, unscrew the retaining ring and
cylinder head from the cylinder barrel.
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.
2. Remove the cylinder rod assembly from the cylinder
barrel and cover the barrel to avoid contamination.
CAUTION
Do not scratch the grooved and gland surfaces.
NOTE: Align old seals in order of removal to facilitate
installation of new seals.
3. Remove the guide lock ring at the top of the piston to
gain access to the setscrew securing the piston to the
cylinder rod.
4. Remove the setscrew and discard.
5. Unscrew the piston from the rod.
6. Remove the remaining guide lock ring and hydrolock
seal assembly from the outside of the piston.
2-64
CAUTION
Published 01-29-2014, Control # 496-00
TMS800E SERVICE MANUAL
7. Remove the O-ring and backup rings from the inside of
the piston.
8. Remove the spacer from the rod and the wear rings from
the spacer.
9. Remove the cylinder head from the rod.
10. Remove the O-ring and backup ring from the outside of
the cylinder head.
11. Remove the wear ring, buffer seal and rod seal from the
inside of the head.
12. Remove the retaining ring from the rod.
13. Remove the wiper ring and backup ring from the inside
of the retaining ring.
14. If necessary, remove the holding valve.
Inspection
1. Clean all parts with solvent and dry with compressed air.
Inspect all parts for serviceability.
CAUTION
Clean all surfaces and remove all burrs and nicks.
Replace all damaged or worn parts.
2. Stone out minor blemishes and polish with fine crocus
cloth.
3. Clean with solvent and dry with compressed air parts
that have been stoned and polished.
4. Inspect the barrel for scoring.
Assembly
1. If removed, install the holding valve. Refer to Valves,
page 2-22.
CAUTION
Do not scratch the grooved and gland surfaces or
damage the seals and O-rings.
NOTE: Lubricate new seals and rings with clean hydraulic
oil. Orient wear ring gaps 180° apart.
NOTE: When installing seals in step 2 through 4, see
Figure 2-46.
2. Install the wiper ring and backup ring into the inside of
the retaining ring.
3. Install the rod seal, buffer seal and wear ring in the inside
of the cylinder head. Make sure the seals are properly
assembled and installed in the correct direction.
4. Install the O-ring and backup ring onto the outside of the
head.