JLG 500RTS ANSI Service Manual - Manual (Page 22)

SECTION 2 - PROCEDURES
2-6 – JLG Sizzor – 3120696
CYLINDERS WITH DOUBLE HOLDING VALVES. BEFORE REMOV-
ING HOLDING VALVES CRACK BLEEDER TO RELEASE PRES-
SURE.
3. If applicable, remove the cartridge-type holding
valve and fittings from the cylinder port block. Dis-
card o-rings.
4. Place the cylinder barrel into a suitable holding fix-
ture. Tap around outside of cylinder head retainer
with a suitable hammer to shatter loctite.
5. Using a suitable spanner wrench, loosen the cylin-
der head retainer, if applicable, and/or cylinder head
gland, and remove from cylinder barrel.
NOTE: Steer Cylinder has two head retainers at each end of
cylinder.
Platform Ext. Cylinder has a snap ring in barrel end
of cylinder. Remove snap ring before withdraw of the
rod.
6. Attach a suitable pulling device to the cylinder rod
port block end or cylinder rod end, as applicable.
EXTREME CARE SHOULD BE TAKEN WHEN REMOVING THE CYL-
INDER ROD, HEAD, AND PISTON. AVOID PULLING THE ROD OFF-
CENTER, WHICH COULD CAUSE DAMAGE TO THE PISTON AND
CYLINDER BARREL SURFACES.
7. With the barrel clamped securely, apply pressure to
the rod pulling device and carefully withdraw the
complete rod assembly from the cylinder barrel.
8. Using suitable protection, clamp the cylinder rod in
a vise or similar holding fixture as close to the piston
as possible.
NOTE: On the Steer Cylinder, the rod and piston are all one
unit.
9. Remove the set screw(s), if applicable, and nut
which attach the piston to the rod, and remove the
piston. Discard nylon point set screws.
10. Remove the piston rings.
11. Remove and discard the piston o-rings, seal rings,
and backup rings.
12. Remove the set screw, if applicable, piston spacer,
and wear ring, if applicable, from the rod.
13. Remove the rod from the holding fixture. Remove
the cylinder head gland and retainer, 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 cleaning
solvent.
2. Inspect the 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 dam-
age. Dress threads as necessary.
4. Inspect inner surface of cylinder barrel tube for scor-
ing 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 and scoring and
for distortion. Dress piston surface or replace piston
as necessary.
7. Inspect seal and o-ring grooves in piston for burrs
and sharp edges. Dress applicable surfaces as nec-
essary.
8. Inspect cylinder head inside diameter for scoring or
other damage and for ovality and tapering. Replace
as necessary.
9. Inspect seal and o-ring grooves in head for burrs
and sharp edges. Dress applicable surfaces as nec-
essary.
10. If applicable, inspect cylinder head retainer or end
cap for surface or thread damage. Repair or replace
as necessary.
11. Inspect cylinder head outside diameter for scoring
or other damage and ovality and tapering. Replace
as necessary.
12. If applicable, inspect thread ring for scoring or other
damage. Dress threads or applicable surfaces as
necessary.
13. If applicable, inspect rod and barrel bushings for
signs of correct lubrication and excessive wear.
Replace as necessary.
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.