SkyTrak 6036 Service Manual - Manual (Page 337)

8.121 Model 6036 Legacy
Hydraulic System
d. Frame Sway Cylinder Inspection and Repair
1. Inspect all parts for wear, damage, etc. If inner
surfaces of the cylinder (Fig. 8-79, 1) do not display
an ultra-smooth, polished finish, or are damaged in
any way, replace the damaged part. Often, dirty
hydraulic fluid causes failure of internal seals and
damage to the polished surfaces within the
component.
2. Inspect the inside of the tube (Fig. 8-79, 5) for
scoring and other damage. If the tube is damaged,
replace it with a new tube.
3. Remove small scratches on the rod or inside of the
tube with very fine grit emery cloth. Use the emery
cloth in a rotary motion to polish out and blend
scratch(es) into the surrounding surface.
4. Clean the parts with trichlorethylene after repair.
5. Check that the rod (Fig. 8-79, 6) is straight. If the rod
is bent, install a new rod.
e. Frame Sway Cylinder Assembly
Note: Follow Section 8.13.3, “General Cylinder Assembly
Instructions.”
1. Install the deep Z-seal with rod back-up (Fig. 8-79, 17)
into the head gland, orienting the edge (20).
2. Install the precision wearband (Fig. 8-79, 16) into
the head gland.
3. Install the heavy-duty rod wiper (Fig. 8-79, 15) with
the raised portion of the lip seal (19) oriented toward
the rod eyelet. The wiper lip (19) 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.
4. Install a new oiled o-ring (Fig. 8-79, 14), back-up
ring (13) and oiled o-ring (12) onto the head gland
(4). If the back-up ring is not flat on both sides, the
side with the arc must be toward the o-ring.
5. Install the head gland (Fig. 8-79, 4) onto the rod (6).
If necessary, use a soft hammer to drive the head
gland onto the rod.
6. Install the new small oiled o-ring (Fig. 8-79, 9) into
the piston (8).
7. Install the capped T-seal (Fig. 8-79, 11) onto the
piston (8).
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” seal band.
8. Install the two precision wearbands (Fig. 8-79, 10)
onto the piston (8).
9. Install the piston (Fig. 8 -79, 8) onto the rod (6).
10. Secure the rod eyelet in a soft-jawed vise or other
suitable holding device. Place a padded support
below the threaded end of the rod to help prevent
damaging the rod.
11. Apply Loctite Primer “T” and Threadlocker #271
(red), to a new locknut (Fig. 8 -79, 7) in accordance
with Loctite instructions. Install the nut onto the
threaded end of the rod (6). Torque the nut to
1100-1250 lb/ft (1492-1695 Nm).
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 (Fig. 8-79, 5).
12. Fasten the tube (Fig. 8-79, 5) in a soft-jawed vise or
other suitable holding device.
13. To aid in installation, lubricate the o-rings and the
inside of the tube, piston and head gland with clean,
filtered hydraulic oil.
IMPORTANT: Use a suitable installation tool or
compression sleeve to help prevent twisting or damaging
the seals and o-rings when installing the piston (Fig. 8-79, 8)
and head gland (4) into the cylinder. When sliding the
rod and piston assembly into the tube, DO NOT damage
the piston by scraping it against the threads in the tube.
Keep the rod in line with the tube to prevent binding.
14. Keep the rod (Fig. 8-79, 6) straight, and carefully
insert the rod into the tube (5). Avoid scratching,
nicking or damaging the tube while installing the rod.
15. Begin threading the head gland (Fig. 8-79, 4) into
the tube (5). Place the locking insert (3) in its hole in
the head gland threads just before the hole is threaded
into the tube. Use a suitable pin spanner wrench to
thread the head gland (4) completely into the tube (5).
Torque the head gland to 300-400 lb/ft (407-542 Nm).
16. Lubricate the pilot-operated check valves (Fig. 8-79, 2)
with clean, filtered hydraulic oil. Using new oiled
o-rings, thread the pilot-operated check valves into
tube (5). Torque valves to 35-40 lb/ft (47-54 Nm).
17. Test the cylinder at low operating pressure (100 psi
or 6,9 bar) to verify that the piston and rod move
freely in both directions.
18. Increase the operating pressure to the maximum for
the cylinder (3250 psi or 224 bar), and check for external
leakage and for free movement in both directions.
19. Retract the piston fully.