SECTION 4 - BASIC HYDRAULIC INFORMATION & SCHEMATICS
4-24
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15.
If applicable, remove the piston spacer from the
rod.
16.
Remove the rod from the holding fixture.
Remove the cylinder head gland and retainer
plate, if applicable. Discard the o-rings, back-up
rings, rod seals, and wiper seals.
Cleaning and Inspection
1.
Clean all parts thoroughly in an approved clean-
ing solvent.
2.
Examine the cylinder rod for scoring, tapering,
ovality, or other damage. If necessary, dress rod
with Scotch Brite or equivalent. Replace rod if
necessary.
3.
Examine threaded portion of rod for excessive
damage. Dress threads as necessary.
4.
ExamineExamine inner surface of cylinder barrel
tube for scoring or other damage. Check inside
diameter for tapering or ovality. Replace if neces-
sary.
5.
Examine threaded portion of barrel for damage.
Dress threads as necessary.
6.
Examine piston surface for damage and scoring
and for distortion. Dress piston surface or
replace piston as necessary.
7.
Examine threaded portion of piston for damage.
Dress threads as necessary.
8.
Examine seal and o-ring grooves in piston for
burrs and sharp edges. Dress applicable surfaces
as necessary.
9.
Examine cylinder head inside diameter for scor-
ing or other damage and for ovality and taper-
ing. Replace as necessary.
10.
Examine threaded portion of head for damage.
Dress threads as necessary.
11.
Examine seal and o-ring grooves in head for
burrs and sharp edges. Dress applicable surfaces
as necessary.
12.
Examine cylinder head outside diameter for
scoring or other damage and ovality and taper-
ing. Replace as necessary.
13.
If applicable, Examine 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 installa-
tion.
b.
Examine steel bushing for wear or other
damage. If steel bushing is worn or dam-
aged, rod/barrel must be replaced.
c.
Lubricate inside of 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.
Examine travel limiting collar or spacer for burrs
and sharp edges. If necessary, dress inside diam-
eter surface with Scotch Brite or equivalent.
15.
If applicable, examine port block fittings and
holding valve. Replace as necessary.
16.
Examine the oil ports for blockage or the pres-
ence of dirt or other foreign material. Repair as
necessary.
17.
If applicable, examine piston rings for cracks or
other damage. Replace as necessary.
Assembly
NOTE:
Prior to cylinder assembly, ensure that the proper
cylinder seal kit is used. See your JLG Parts Manual
for these machine models.
Apply a light film of hydraulic oil to all components prior
to assembly.
STEEL
BUSHING
GAR-MAX
BUSHING
ARBOR
Figure 4-21. Gar-Max Bearing Installation
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