Counterweight Removal Cylinder; Description; Maintenance - Manitowoc Grove RT765E-2 Service And Maintenance Manual

RT765E-2 SERVICE MANUAL

COUNTERWEIGHT REMOVAL CYLINDER

Description

The counterweight cylinder Figure 2-50 has a 3.5 in (8.9 cm)
diameter bore.
The retracted length of the cylinder from the end of the barrel
to the center of the rod lug is 39.19 in ±0.09 (99.5 cm ±0.22).
The stroke of the cylinder is 28.0 in (71.12 cm) which gives
an extended length of 67.19 in ±0.09 (170.66 cm ±0.22).
A wiper ring prevents foreign material from entering the
cylinder. O-rings and other seals prevent internal and
external leakage.
The cylinder weighs approximately 92 lb (41.7 kg).

Maintenance

Disassembly
NOTE: Any maintenance requiring disassembly of the
cylinders should include replacement of all seals
and rings. A seal kit will supply the required items.
1. Remove the holding valve from the port block.
2. Remove the bolts, washers, and nuts securing the rod
end lug to the cylinder rod and remove the lug.
3. Clean away all dirt from the head. Place protective
padding around the rod near the head to prevent
damaging the chrome during head removal. Using a
spanner wrench, unscrew the head from the barrel.
CAUTION
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. Injury may result from the cylinder rod
unexpectedly exiting the cylinder barrel.
CAUTION
Exercise extreme care when handling or setting down the
rod. Damage to the rod surface may cause unnecessary
maintenance and expense.
4. Remove the rod and attached parts from the barrel.
NOTE: Cover the barrel opening to avoid contamination.
CAUTION
When removing seals and rings, avoid scratching the
grooved and gland surfaces.
GROVE
NOTE: Arranging discarded seals and rings in the order of
disassembly will aid in installation of new seals and
rings. Pay attention to how each seal and ring is
installed to avoid installing replacement seals and
rings improperly.
5. Loosen and remove the locknut securing the piston.
Remove the piston from the rod.
6. Remove the wear ring and piston seal from the outside
of the piston.
7. Remove the spacer from the rod.
8. Remove the head from the rod.
9. Remove the O-rings and the backup ring from the
outside of the head. Remove the rod seal, wiper ring and
o-ring from the inside of the head.
Inspection
1. Clean all parts with solvent and dry with compressed air.
Inspect all parts for serviceability.
2. Inspect the barrel carefully for scoring. If barrel is
scored, it must be repaired or replaced.
3. Check piston for damage. If piston is damaged,
determine if it can be repaired or must be replaced.
4. Inspect rod for straightness. Determine if it can be
straightened or must be replaced. Verify internal
passages and ports are clean and undamaged.
Before installing new seals and rings, clean all surfaces
and carefully remove burrs and nicks. Parts displaying
excessive wear or damage should be replaced.
5. Stone out minor blemishes and polish with a fine crocus
cloth.
6. Clean with solvent and dry with compressed air any
parts that have been stoned and polished.
Assembly
When installing new seals and rings, avoid stretching
seals or scratching the grooved or gland surfaces. Make
sure parts are clean before and during assembly. Make
sure seals and rings are installed in the proper order.
NOTE: Lubricate seals and rings with clean hydraulic oil.
NOTE: Make sure the gaps of the two wear rings are 180
degrees apart.
Published 9-04-2014, Control # 422-08
HYDRAULIC SYSTEM
CAUTION
CAUTION
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