SkyTrak 8042 Service Manual - Manual (Page 544)

8.129 Model 8042, 10042, 10054 Legacy Rev. 10/03
Hydraulic System
5. Using a pin spanner wrench, unscrew the locking collar
(7) from the tube (3). The locking collar was
originally torqued to 300-400 lb-ft (407-542 Nm), so
a considerable amount of force is required.
6. Carefully slide the locking collar (7) and the head
gland (8) down along the rod toward the eyelet end,
away from the cylinder tube (3).
IMPORTANT: When sliding the rod and piston assembly
out of the tube, prevent the threaded end of the tube
from damaging the piston (9). Keep the rod centered
within the tube to help prevent binding.
7. Carefully pull the rod (6) with all attachments straight
out of the tube (3).
8. Fasten the rod in a soft-jawed vise, and put a
padded support below and near the threaded end of
the rod to help prevent damage to the rod.
9. Remove the locknut (10) from the rod (6). The nut was
installed with Loctite #271 (red) and torqued to 1750-
2000 lb-ft (2373-2712 Nm).
Note: It may be necessary to apply heat to break the
bond of the sealant between the locknut (10) and the rod
(6) before the piston (9) can be removed. Some parts of
cylinders are sealed with a special organic sealant and
locking compound.
Before attempting to disassemble these parts, remove
any accessible seals from the area of the bonded joint.
Wipe off any hydraulic oil and heat the joint uniformly to
break the bond. A temperature of 300-400° F (149-204° C)
will destroy the bond. Avoid overheating or the parts may
become distorted or damaged. Apply sufficient torque or
pressure for removal while the parts are still hot.
Breakdown of sealant will leave a white, powdery
residue on threads and parts. Clean the residue away
with a soft brass wire brush prior to reassembly, and
wipe with Loctite “T” cleaner before reinstallation.
10. Remove the piston (9) from the rod (6).
11. Remove both precision wearbands (11) and the
capped T-seal (12) from the piston (9).
Note: The T-seal actually consists of four components: a
wide, flexible inner band, the flexible T-seal band itself,
and two supportive split caps that mount on either side of
the “T” itself.
MH2890
2
3
4
5
6
7
8
9
10
11
12