SkyTrak 8042 Service Manual - Manual (Page 530)

8.115 Model 8042, 10042, 10054 Legacy Rev. 10/03
Hydraulic System
For Current Production
b. Attachment Tilt 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 attachment tilt cylinder (24) with a suitable
cleaner before inspection. Remove all dirt, debris
and grease from the cylinder.
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 tube (25).
2. If necessary, remove the grease fitting (26) from the
end of the rod (27).
3. Clamp the trunnion end of the attachment tilt
cylinder in a soft-jawed vise or other acceptable
holding equipment if possible.
4. Slowly remove the 4000 psi (276 bar) counterbalance
valve (28) and the pilot-operated check valve (29)
from the attachment tilt cylinder.
5. Extend the rod (27) to allow access to the base of
the cylinder.
IMPORTANT: Protect the finish on the rod at all times.
Damage to the surface of the rod can cause seal failure.
6. Remove the lock screw (30) from the flange of the
head gland (31).
7. Using a pin spanner wrench, unscrew the head
gland (31) from the tube (25). The head gland was
originally torqued to 300 ±50 lb-ft (407 ±68 Nm), so
a considerable amount of force is required to remove
it. Carefully slide the head gland down along the rod
toward the eyelet end, away from the cylinder tube.
8. When sliding the rod and piston assembly in the
tube, prevent the threaded end of the tube from
damaging the piston (32). Keep the rod centered
within the tube to help prevent binding.
MH4290
24
25
26
27
28
29
30
31
32
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.