Lull 944E-42 Service Manual - Manual (Page 498)

Hydraulic System
8.246 Model 644E-42/944E-42 Rev. 6/04
b. Swing Carriage Cylinder Disassembly
Note: An additional o-ring may be included at the base
of the cylinder rod. This additional o-ring may be
discarded, as it served only in a temporarily protective
role.
1. Clean the swing carriage cylinder (1) with a suitable
cleaner to remove dirt, debris, grease, etc.
IMPORTANT: Avoid using excess force when clamping
the cylinder in a vise. Apply only enough force to hold the
cylinder securely. Excessive force can damage the
cylinder.
2. Secure the swing carriage cylinder in a soft-jawed
vise or other acceptable holding equipment if
possible.
3. Slowly remove the 3000 psi (207 bar)
counterbalance cartridge (2) and the 2000 psi
(138 bar) direct-acting relief valve (3) from the swing
carriage cylinder.
4. If the self-aligning bearing (23) requires
replacement, support the rod (4) in a soft-jawed vise
or other suitable holding device. Carefully press the
bearing out of the rod eyelet.
5. Extend the rod (4) to access the cylinder base.
IMPORTANT: Protect the finish on the rod at all times.
Damage to the surface of the rod can cause seal failure.
6. Using a pin spanner wrench, unscrew the head
gland (5) from the cylinder tube (6). The head gland
was originally torqued to 250-300 lb-ft (339-407
Nm), so a considerable amount of force is required.
Carefully slide the head gland down along the rod
toward the eyelet, away from the tube (6).
IMPORTANT: When sliding the rod and piston assembly
in the tube, prevent the threaded end of the tube from
damaging the piston (7). Keep the rod centered within
the tube to help prevent binding.
7. Carefully pull the rod (4) with all attachments straight
out of the tube (6).
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MT1910
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WARNING:
Significant pressure may be
trapped inside the cylinder. Exercise caution
when removing a counterbalance valve or a
pilot-operated check valve from a cylinder.
Escaping hydraulic fluid under pressure can
penetrate the skin, causing death or serious
injury.