Lull 944E-42 Service Manual - Manual (Page 457)

8.205 Model 644E-42/944E-42 Rev. 6/04
Hydraulic System
3. Remove the load shuttle cartridge (8).
4. Remove the accumulator charge logic cartridge (9).
This cartridge has two settings: Low Setting 1050 psi
(72 bar) and High Setting 1950 psi (134 bar).
5. Remove the 2450 psi (168 bar) direct acting relief
valve (10).
6. Remove the inverted shuttle cartridge (11).
7. Remove the pilot directional cartridge (12). Remove
the orifice disc (13) from the port.
8. Loosen the filter nut (14), remove the filter retainer
(15), washer (16) and sintered filter (17) from the
port. Remove the o-ring (18) from the filter retainer
and discard the o-ring.
9. Remove the load sense compensator (19).
10. Remove the check valve cartridges (20).
11. Remove the 550 psi (37 bar) pressure reducing
cartridge (21).
12. Remove the coil assembly (22).
13. Remove the accumulator brake pressure switch (23).
14. Clean all components with a suitable cleaner before
inspection.
15. Inspect internal passageways of the accumulator
charge/secondary function valve and its component
parts for wear, damage, etc. If inner surfaces of the
accumulator charge/secondary function valve DO
NOT display an ultra-smooth, polished finish, or
components are damaged in any way, replace the
accumulator charge/secondary function valve or
appropriate part. Often, dirty hydraulic fluid causes
failure of internal seals and damage to the polished
surfaces within the accumulator charge/secondary
function valve.
Note: ALWAYS replace seals, o-rings, gaskets, etc.,
with new parts to help ensure proper sealing and
operation. Lubricate seals and o-rings with clean
hydraulic oil.
16. Secure the accumulator charge/secondary function
valve (7) in a bench vise or by other suitable means.
17. Install the load shuttle cartridge (8), with new seals,
and torque to 20 lb-ft (27 Nm). Refer to Parts Manual
for seal kits.
18. Install the accumulator charge logic cartridge (9),
with new seals, and torque to 28 lb-ft (38 Nm). Refer
to Parts Manual for seal kits.
19. Install the direct acting relief valve (10), with new
seals, and torque to 20 lb-ft (27 Nm). Refer to Parts
Manual for seal kits.
20. Install the inverted shuttle cartridge (11), with new
seals, and torque to 28 lb-ft (38 Nm). Refer to Parts
Manual for seal kits.
21. Place the orifice disc (13) in the port and install the
pilot directional cartridge (12), with new seals, and
torque to 20 lb-ft (27 Nm). Refer to Parts Manual for
seal kits.
22. Install the new sintered filter (17) followed by the
washer (16) into the port. Secure in place with the
filter retainer (15) and o-ring (18). Torque the retainer
to 18 - 22 lb-ft (24 - 30 Nm). Tighten the filter nut (14)
and torque to 27 - 29 lb-ft (37 - 39 Nm).
23. Install the load sense compensator (19), with new
seals, and torque to 50 lb-ft (68 Nm). Refer to Parts
Manual for seal kits.
24. Install the two check valves (20), with new seals, and
torque to 20 lb-ft (27 Nm). Refer to Parts Manual for
seal kits.
25. Install the pressure reducing cartridge (21), with new
seals, and torque to 20 lb-ft (27 Nm). Refer to Parts
Manual for seal kits.
26. Install the coil assembly (22), with new seals, and
torque to 20 lb-ft (27 Nm). Refer to Parts Manual for
seal kits.
27. Install the accumulator brake pressure switch (23)
with new seals and torque to 15 ±1 lb-ft (20 ±1 Nm).
Refer to Parts Manual for seal kits.
MU2000
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