Lull 6K Service Manual - Manual (Page 463)

Boom and Transfer
Service Manual — Models 644B, 6K, 844C, 8K, 1044C, 10K 6-213
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 and torque to
40–45 ft-lbs.
18. Install valve cartridge (Item 6) in manifold block and torque to
150–160 ft-lbs.
19. Install four O-ring plugs (Item 4) in manifold block and torque to
125–145 in-lbs.
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.
22. Lubricate new O-ring, backup ring, seals, and wear rings with hydraulic
oil and install on head. Using a seal driver, install new wiper seal in
head. Lubricate wiper seal with hydraulic oil.
23. Slide rod bearing head (Item 11) and piston (Item 10) onto rod
(Item 13). Lubricate threads on rod with hydraulic oil and install rod nut
(Item 9). Torque rod nut to 750 ft-lbs.
24. Lubricate threads on eight (8) capscrews (Item 12) with hydraulic oil.
Coat inside of barrel (Item 8) with hydraulic oil. To avoid damaging
seals during assembly, carefully insert rod and head into barrel. Install
capscrews until snug. Do not torque capscrews (instructions follow).
25. Following sequence shown in Fig. 6-10, torque capscrews to an initial
value of 30 ft-lbs. Follow sequence again and torque capscrews to a
final value of 65 ft-lbs.
26. Install two (2) elbows (Item 7) on cylinder barrel. Torque elbow to
75–85 ft-lbs.
27. Install the extension cylinder base mount (Item 3) to the cylinder barrel
as follows.
For Models 1044C-54 (S/N 101–143) and 10K-54 (S/N 101–103):
Install with three (3) each flatwashers (Item 2) and capscrews (Item 1).
Torque capscrews to 200 ft-lbs.
For Models 1044C-54 (S/N 144–) and 10K-54 (S/N 104–):
Install with two (2) each flatwashers (Item 2) and capscrews (Item 1).
Torque capscrews to 680 ft-lbs.