JLG T500J, Service And Maintenance Manual

Page: 194 / 306

SECTION 5 - BASIC HYDRAULIC INFORMATION & SCHEMATICS
5-20 3121200
REMOVE SEALS USING A BRASS OR PLASTIC PICK ONLY. DO NOT USE A KNIFE,
SHARP OBJECT, OR SCREW DRIVER. NOTE SEAL ORIENTATION BEFORE REMOV-
ING FOR PROPER INSTALLATION.
9. Remove locknut (6) from the rod (2).
10. Screw piston counterclockwise and remove from rod.
11. Remove and discard o-ring (7), backup rings (14) and

o-ring (8) from piston (4).
12. Remove spring (5) and spacer (13) from rod (2).
13. Remove rod from holding fixture.
14. Remove and discard wiper seal (12), rod seal (11) from
cylinder head (3).
CLEANING AND INSPECTION
1. Clean parts thoroughly with approved cleaning solvent.
2. Inspect cylinder rod for scoring, tapering, ovality, or
other damage. If necessary, dress rod with Scotch Brite
or equivalent. Replace rod if necessary.
3. Inspect threaded portion of rod for excessive damage.
Dress threads as necessary.
4. Inspect inner surface of cylinder barrel tube for scoring
or other damage. Check inside diameter for tapering or
ovality. Replace if necessary.
5. Inspect threaded portion of barrel for damage. Dress
threads as necessary.
6. Inspect piston surface for damage, scoring, or distortion.
Dress piston surface or replace piston as necessary.
7. Inspect threaded portion of piston for damage. Dress
threads as necessary.
8. Inspect seal and o-ring grooves in piston for burrs and
sharp edges. Dress surfaces as necessary.
9. Inspect cylinder head inside diameter for scoring or
other damage, and for ovality and tapering. Replace as
necessary.
10. Inspect threaded portion of head for damage. Dress
threads as necessary.
11. Inspect seal and o-ring grooves in head for burrs and
sharp edges. Dress applicable surfaces as necessary.
12. Inspect cylinder head outside diameter for scoring,
damage, ovality, and tapering. Replace as necessary.
13. Inspect travel limiting collar or spacer for burrs and
sharp edges. If necessary, dress inside diameter surface
with Scotch Brite or equivalent.
14. If applicable, inspect port block fittings and holding
valve. Replace as necessary.
15. Inspect oil ports for blockage or presence of dirt or other
foreign material. Repair as necessary.
16. If applicable, inspect piston rings for cracks or other
damage. Replace as necessary.
MAE29310
4
8
7
14
14
Figure 5-25. Piston Disassembly
MAE29320
3
11
12
Figure 5-26. Cylinder Head Disassembly