Lull 1044C-54 Series II Service Manual - Manual (Page 257)

Boom and Transfer
31200079 6-115
a. Place socket wrench over counterbalance valve cartridge. Wrap a
clean shop rag around the socket to cover the area of the
counterbalance valve cartridge.
b. Carefully and slowly, turn cartridge out of manifold block to release
pressure in cylinder.
4. Remove the counterbalance valve cartridges.
5. Slowly extend and retract cylinder by hand to remove most of the
hydraulic oil.
6. Remove one (1) setscrew (Item 12) securing rod bearing head
(Item 11) to cylinder barrel.
7. Remove cylinder rod (Item 13) from cylinder barrel.
CAUTION: To prevent possible damage to components, support rod and
head; do not wiggle rod or head back and forth during
removal.
8. Remove rod nut (Item 9), piston (Item 10), tube (Item 14) and rod
bearing head from cylinder rod.
9. Remove the two (2) elbows (Item 7) from cylinder barrel.
10. Remove four (4) O-ring plugs (Item 4) from cylinder manifold block.
11. Remove all O-rings, wear rings, and backup rings from cylinder
components and discard.
12. Thoroughly clean components with solvent and dry with compressed
air. Inspect and replace if damaged.
13. Inspect inner surface of barrel, outer surface of piston, and length of
rod for scratches and scoring. If barrel, piston, or rod is damaged, it
must be replaced.
14. Check condition of threads on rod, nut, and capscrews. Do not attempt
to repair damaged threads.
15. Inspect counterbalance valve cartridges (Items 5 and 6), including
O-rings, for condition and replace as necessary. Do not disassemble
cartridges. Service to counterbalance valve cartridges is limited to
installing new O-rings and replacing the entire cartridge.
16. Lubricate counterbalance valve cartridge O-rings with clean hydraulic
oil.
17. Install valve cartridge (Item 5) in manifold block.
18. Install valve cartridge (Item 6) in manifold block.
19. Install four O-ring plugs (Item 4) in manifold block.
20. Lubricate new O-ring with hydraulic oil and install inside piston (seals
rod to piston).
21. Lubricate new seal and wear rings with hydraulic oil and install on
piston.