JLG 450A_AJ Series II Service Manual - Manual (Page 313)

SECTION 5 - HYDRAULICS
3121180 – JLG Lift – 5-23
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 nec-
essary.
12. Inspect cylinder head outside diameter for scoring
or other damage and ovality and tapering. Replace
as necessary.
13. If applicable, inspect rod and barrel bearings for
signs of correct excessive wear or damage. Replace
as necessary.
a. Thoroughly clean hole, (steel bushing) of burrs,
dirt etc. to facilitate bearing installation.
b. Inspect steel bushing for wear or other damage.
If steel bushing is worn or damaged, rod/barrel
must be replaced.
c. Lubricate inside of the steel bushing with WD40
prior to bearing installation.
d. Using an arbor of the correct size, carefully
press the bearing into steel bushing.
NOTE: Install pin into the Gar-Max bearing dry. Lubrication is
not required with nickel plated pins and bearings.
14. Inspect travel limiting collar or spacer for burrs and
sharp edges. If necessary, dress inside diameter
surface with Scotch Brite or equivalent.
15. If applicable, inspect port block fittings and holding
valve. Replace as necessary.
16. Inspect the oil ports for blockage or the presence of
dirt or other foreign material. Repair as necessary.
17. If applicable, inspect piston rings for cracks or other
damage. Replace as necessary.
Assembly
NOTE: Use proper cylinder seal kit for cylinder assembly.
See your JLG Parts Manual.
Apply a light film of hydraulic oil to all components
before assembly.
1. A special tool is used to install a new rod seal into
applicable cylinder head gland groove.
ENSURE SEALS ARE INSTALLED PROPERLY WHEN INSTALLING
‘POLY-PAK’ PISTON SEALS. REFER TO WIPER SEAL INSTALLA-
TION FOR CORRECT SEAL ORIENTATION. IMPROPER SEAL
INSTALLATION CAN CAUSE CYLINDER LEAKAGE AND IMPROPER
CYLINDER OPERATION.
Figure 5-25. Gar-Max Bearing Installation
Figure 5-26. Rod Seal Installation