Manitowoc Grove RT770E Service Maintenance Manual page 117

RT770E
7. Stone out minor blemishes and polish with a fine crocus
cloth.
8. Clean with solvent and dry with compressed air any
parts that have been stoned and polished.
Assembly
CAUTION
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.
1. Install the rod seal, wear ring and wiper ring in the inside
of the head and the O-ring and backup ring on the
outside of the head.
2. Install the wear rings and piston seal on the outside of
the piston.
CAUTION
Exercise extreme care when handling the rod. Damage to
the rod surface may cause unnecessary maintenance
and expense. Also, take care to avoid damaging grooved
or gland surfaces or rings or seals during rod insertion.
3. Clean all oil from the threads of the head. Coat the
threads with an anti-seize compound (ex: Never-Seez
paste lubricant or similar lubricant).
GROVE
4. Slide the head onto the rod. The head will have to be
tapped on with a rubber mallet to engage the seals.
Push the head about half way down the length of the rod
assembly. Install the spacer and piston onto the rod.
5. Install the locknut on the rod.
6. With the hoist, raise the rod assembly back into a
vertical position taking care not to damage the OD of the
seals on the head and piston.
7. Remove the cover from the barrel.
8. Lubricate the OD of the seals on the piston and head
with clean light hydraulic oil and lower the assembly into
the barrel. Stop just before the head enters the barrel.
9. Place the spanner wrench on the head and turn
counterclockwise until the thread clicks, then reverse
direction to clockwise and thread in until there is no gap
between the shoulder of the head and the top of the
barrel.
Do not use air pressure to cycle or pressurize the cylinder.
Damage to the seals may result.
10. Pressurize and cycle the cylinder with hydraulic oil
pressure. Static test the cylinder at 206.7 bar (3000 psi).
Check for proper operation and any leakage. Make
repairs as needed.
Published 11/26/2014, Control # 447-05
HYDRAULIC SYSTEM
CAUTION
2
2-77