SkyTrak 8042 Service Manual - Manual (Page 580)

8.165 Model 8042, 10042, 10054 Legacy Rev. 10/03
Hydraulic System
9. Fasten the rod end 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.
10. Remove the precision wear band (10) from the
piston (9).
11. Remove the two setscrews (11), and nylon balls
(12), from the piston (9). Pry or drill out the nylon
balls as required. DO NOT damage the piston
threads. New nylon balls will be required for
reassembly.
12. Remove the piston (9) from the rod (5). The piston
was originally torqued to 425-500 ft-lb (576-678 Nm)
so a considerable amount of force will be required to
remove the piston.
13. Remove the piston square seal (13) and square ring
(14) from the piston (9).
14. Remove the small o-ring (15) from the groove in the
end of the rod (5).
15. Remove the head gland (7) from the rod (5).
16. Remove the o-ring (16), back-up ring (17) and o-ring
(18) from the head gland (7).
17. From within the head gland (7), remove the precision
wearbands (19) and the deep Z-seal (20). From the
other end, remove the rod wiper (21).
c. Swing Carriage Cylinder Cleaning
1. Remove all hydraulic fluid, dirt and debris from the
swing carriage cylinder (1).
2. Discard all seals, back-up rings and o-rings. Replace
with new items from the complete seal kits (22) to
help ensure proper cylinder function.
3. Clean all metal parts with an approved cleaning
solvent such as trichlorethylene. Carefully clean
cavities, grooves, threads, etc.
d. Swing Carriage Cylinder Inspection
1. Inspect internal surfaces and all parts for wear,
damage, etc. If the inner surface of the tube (8) does
not display a smooth finish, or is scored or damaged
in any way, replace the tube. Often, dirty hydraulic
fluid causes failure of internal seals and damage to
the smooth surface within the tube.
2. Remove slight scratches on the piston, rod or inner
surface of the tube with very fine grit emery cloth.
Use the emery cloth in a rotary motion to polish out
and blend the scratch(es) into the surrounding
surface.
3. Clean parts with trichlorethylene after repair.
4. Check that the rod (5) is straight. If it is bent, install a
new rod.
e. Swing Carriage Cylinder Assembly
Note: Follow the information in Section 8.13.3, “General
Cylinder Assembly Instructions.”
1. Install the deep Z-seal (20), orienting the edge (23).
Install the precision wearbands (19) into the forward
end of the head gland (7), and at the rear end, install
the rod wiper (21). The wiper lip (24) should be
toward the outer end of the head gland and the seal
lips toward the inner end of the head gland. Use
tools that will not damage the seals.
2. Install a new oiled o-ring (18), back-up ring (17) and
oiled o-ring (16) onto the head gland (7).
3. Fasten the rod end 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.
4. Push the head gland (7) onto the rod (5). If
necessary, use a soft hammer to drive the head
gland onto the rod.
5. Install a new small oiled o-ring (15) into the groove in
the end of the rod (5).