SkyTrak 6036 Service Manual - Manual (Page 140)

Section 9. Hydraulic System
9-27 Model 6036 S/N 9B0499 and Before
9.2.2 Boom Extend Cylinder
a. Removal
1. Retract the boom and support it in a horizontal
and level position with blocking.
2. Engage the park lock, place the travel select
lever in neutral, and stop the engine.
3. Operate the hydraulic controls after the engine
has stopped to relieve any trapped pressure.
4. Disconnect the hydraulic lines from the extend
cylinder and cap or plug open connections.
5. Remove the anti-buckle bar, Fig. 9.11.
6. Support the extend cylinder with a sling or
other suitable device.
Warning !
Warning !
4. Have a helper start the forklift engine.
5. Position the hoist cylinder so that the rod is
aligned with the rod end mounting holes as
much as possible.
6. Instruct the operator to raise or lower the hoist
cylinder slowly until the rod end eye is aligned
with the outer boom mounting holes. Secure
the rod end to the boom with pivot pin and its
locking capscrew and locknut.
7. Raise the boom as far as it will go; then lower
it as far as it will go five times or until the
operation of the boom hoist cylinders is normal
(no jerks or spongy feel).
8. Shut down the engine. Check the hydraulic oil
level and fill as described in the Owners/
Operators Manual.
9. Test boom hoist/lower circuit operation as
described in paragraph 9.1.1c.
Fig. 9.11 Boom Extend Cylinder Removal
Wait for the hydraulic fluid to cool before servic-
ing any hydraulic component. Hot hydraulic fluid
can cause severe burns.
7. Remove the rod end pin and retaining rings
attaching the rod end of the extend cylinder to
the intermediate boom.
8. Remove the base end pin and retaining rings
securing the base end of the cylinder to the
outer boom.
9. Remove the cylinder from the forklift using a
strap sling and hoist or other suitable equip-
ment.
b. Disassembly
1. Remove all dirt and grease from the cylinder.
2. Fasten the cylinder in a soft-jawed vise or
other acceptable holding equipment. Do not
damage the tube.
3. Remove the counterbalance valve (14, Fig.
9.12), pilot check valve (15) and related O-
rings (18) and backup rings (19) from the tube
(13).
IMPORTANT: Do not attempt to reset the extend
cylinder counterbalance valve cartridge. If re-
placement is necessary, replace the cartridge with
a new one.
4. Using a pin spanner wrench, unscrew the
gland (12, Fig. 9.13) from the tube (13).
IMPORTANT: Protect the finish on the rod at
all times. Damage to the surface of the rod can
cause premature seal failure.
5. Pull the rod and piston assembly straight out
of the tube.
IMPORTANT: When sliding the rod and piston
assembly out of the tube, be careful so that gland
threads in the tube do not damage the piston (5).
Keep the rod in line with the tube barrel to prevent
binding.
6. Remove piston seal (4) from the piston.
Relieve hydraulic pressure before servicing any
hydraulic component. Escaping hydraulic fluid
under pressure can penetrate the skin causing
serious injury.
ANTI-BUCKLE BAR
ROD
END PIN
BASE END
PIN
EXTEND
CYLINDER
MA0521