SkyTrak 3606 Service Manual - Manual (Page 283)

Hydraulic System
9-89
c. Attachment Tilt Cylinder Cleaning
1. Thoroughly clean the inner surface of the attachment
tilt cylinder (Fig. 9– 64) with trichlorethylene or
another approved cleaner.
2. Discard all seals, backup rings and O-rings. Replace
with new items from a complete seal kit 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.
Note: If a white, powdery residue is present on threads
and parts, it can be removed. Clean the residue away
with a soft brass wire brush prior to reassembly, and wipe
with Loctite “T” cleaner before reinstallation.
d. Attachment Tilt Cylinder Inspection
1. Inspect internal surfaces and all parts for wear,
damage, etc. If inner surface of the tube (3, Fig. 9–
64) does not display a smooth finish, or is scored or
damaged in any way, replace the tube. Most often,
dirty hydraulic fluid causes failure of internal seals
and damage to the smooth surface within the tube.
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.
2. Inspect all other components for wear, damage, etc.
Clean parts with trichlorethylene.
3. Check that the rod (18) is straight. If it is bent, a new
rod must be installed.
e. Attachment Tilt Cylinder Assembly
Note: Follow Section 9.10 c. General Cylinder Assembly
Instructions.
1. If the bushings (17, Fig. 9– 64) need replacement,
support the rod (18) in a soft-jawed vise or other
suitable holding device. Carefully press the bushings
into the rod eyelet. Install the grease fittings and
lubricate with multi-purpose grease after installing
the attachment tilt cylinder onto the inner boom.
2. Install the small O-ring (8) into the rod-end of the
piston (6).
IMPORTANT: Install the sealed outside diameter heavy-
duty rod wiper (16) into the outside end of the head gland
(14).
3. Install both precision wearbands (5) and the Type
730 capped T-seal (7) onto the piston (6).
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.
4. Install the O-ring (9), back-up ring (10), O-ring (11),
precision wearband (12) and deep Z-seal with rod
backup (13) onto the head gland (14).
5. Install the head gland (14) and piston (6) onto the rod
weldment (18).
IMPORTANT: When sliding the rod and piston assembly
in the tube, prevent the threaded end of the tube from
damaging the piston (6). Keep the rod centered within the
tube to help prevent binding.
6. Place the attachment tilt cylinder in a soft-jawed vise
or other acceptable holding equipment if possible.
DO NOT damage the tube. Carefully insert the rod
(18) with all attachments straight into the tube (3).
IMPORTANT: Protect the finish on the rod at all times.
Damage to the surface of the rod can cause seal failure.
7. Fasten the eye of 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.Apply
Loctite #271 (red) and install the 1.50-12 NF lock nut
(4) onto the rod (18). Torque the nut to 1100-1250 lb/
ft (1492-1695 Nm). The threads will deform upon
tightening, locking the nut in place.
8. Using a pin spanner wrench, thread the head gland
(14) almost completely into the tube (3), leaving just
enough room to install a new locking insert (15) into
its hole in the head gland threads.
9. Install a new locking insert (15). Thread the head
gland tightly into the tube and torque to 300-400 lb/ft
(407-542 Nm).
10. Thread the two 4000 psi (276 bar) counterbalance
valves (2) into the attachment tilt cylinder. Torque to
30-35 lb/ft (41-47 Nm).
11. If necessary, install a grease fitting into the tapped
hole in the end of the rod weldment (18). Lubricate
the bearings in the rod end through the grease fitting
with multi-purpose grease before the vehicle is
operated.
f. Attachment Tilt Cylinder Installation
1. Screw an eyelet, hook, or other suitable fastener into
the tapped hole on top of the attachment tilt cylinder
(Fig. 9– 64). Make sure the device used can actually
support the cylinder. Attach a suitable sling to an
overhead crane or other suitable device and to the
attachment tilt cylinder at the eyelet or hook. Place
the attachment tilt cylinder in position within the
gooseneck. Refer to Section 3 Boom as required.
Model 3606 • Origin 10/99