Section
4-20 LX 31/41 Work Platform
Maintenance
4.10
Note: During seal replacement steps, do not use
sharp edged tools to avoid cutting the seals. After
assembling all seals, allow at least one hour for the
seals to elastically restore to their original shape
before assembly. Refer to Figure 4-16 for component
identification and placement.
11. Separate the three components of the piston seal.
Stretch the rubber inner ring over the piston and
into the seal groove. Warm the teflon outer ring to
150
o
f using heated hydraulic fluid or water. Stretch
the teflon outer ring into the seal groove. Clean the
groove in the teflon ring and install the quad ring.
Verify that none of the rings have twisted.
12. Install the glass filled nylon wear rings into the outer
grooves in the piston.
13. Twist the U-Cup seal into a 'C' shape and allow it to
snap into the groove in the head.
14. Use the above technique to install the wiper into the
head.
15. Install the static o-ring and the static backup ring into
the grove in the head. Verify that the backup ring is
closest to the threads.
16. Install the sealing o-ring between the threads and
the flange lip on the head, be careful not to damage
the o-ring on the threads.
17. Slide the head assembly onto the rod.
18. Install the static o-ring into the groove on the rod.
19. Install the piston onto the rod.
20. Install the slotted nut and torque to 325 to 520 ft.-
lbs. Install the cotter pin. Do not back off on the
slotted nut to install the cotter pin. Once the torque
has reached 325 ft.-lbs., increase until the next slot
aligns with the hole in the rod.
21. Slide the piston, rod, and head into the tube. Be
careful not to damage the piston seal on the threads
during assembly. If necessary, use shimstock to
protect the piston seal when inserting.
22. Use a spanner wrench to tighten the head.
INSTALLATION
1. Remove the pilot operated check valves and com-
pletely fill both ends of cylinder with hydraulic oil.
Replace the pilot operated check valves.
2. Attach both ends of the cylinder to the upper and
lower attachments with cylinder pins.
3. Install the hex nuts onto the cylinder pins, tighten.
4. Remove the jackstands from under the chassis.
5. Operate the work platform over rough terrain and
check for proper function and leaks.
4.10 Axle Cylinder (4WD Only)
REMOVAL (Figure 4-20)
Note: Be sure platform is fully down and that ma-
chine is on level ground.
1. Lift the chassis with a 2 ton jack, and place 1 ton
jackstands underneath the left and right frame
members just behind the articulating axle assembly.
Lower the jack. The weight of the front of the
chassis should now be supported by the jackstands,
and the front wheels should still be allowed to touch
the ground.
2. Remove the four screws from the front axle cover,
remove cover.
3. Remove and cap the hoses.
4. Remove the hex nuts from the cylinder pins at both
ends, remove pins.
5. Remove the cylinder from of the chassis.
SEAL REPLACEMENT (FIGURE 4-17)
Note: Provide a clean work area for this operation,
and observe clean assembly practices. Seals and
hydraulic cylinder components are highly sensi-
tive to contamination that may not even be
visible to the naked eye.
1. Use a spanner wrench to unscrew the head from the
cylinder body tube.
2. Carefully slide the rod, piston, and head out of the
body tube and place on a clean surface.
3. Remove cotter pin from cylinder rod.
4. Unscrew the slotted nut from the rod end.
5. Remove the piston from the rod.
6. Slide the rod out of the head.
7. Remove all of the old seals and wear rings, discard.
8. Thoroughly clean all parts with solvent. Rinse the
inside of the tube and allow to drain. A high pres-
sure rinse and wipe with a lint free rag is preferable.
9. Inspect the rod, head, piston, and tube for scratches,
pits, or polishing. Check seal groves and sealing
surfaces. Scratches or pits deep enough to catch the
fingernail are unacceptable, replace the affected
component. Polishing is a sign of uneven loading,
when this occurs, the surface should be checked for
roundness. Surfaces not round within .007" should
be replaced.
10. Lubricate all components and seals with clean
hydraulic oil prior to assembly.
To Next Page
Loading...
Need help?
General
