JLG 1850SJ Service And Maintenance Manual page 330

SECTION 5 - BASIC HYDRAULIC INFORMATION & HYDRAULIC SCHEMATICS
8. Remove three bolts attaching tapered bushing to pis-
ton.
9. Insert bolts in threaded holes in outer piece of Tapered
Bushing. Alternately tighten bolts until bushing is loose
on piston. Remove tapered bushing from piston.
10. Screw the piston counterclockwise by hand and remove
piston from cylinder rod.
Figure 5-67. Tapered Bushing Removal
REMOVE SEALS USING A BRASS OR PLASTIC PICK ONLY. DO NOT USE A KNIFE,
SHARP OBJECT, OR SCREW DRIVER. MAKE NOTE OF SEAL ORIENTATION
BEFORE REMOVING FOR PROPER INSTALLATION.
11. Remove and discard backup ring (14), O-ring (15), and
backup ring (16) from inside of piston (17). Remove and
discard two lock rings (18), seals (19), and wear ring (20)
from outside of piston.
Figure 5-68. Piston Disassembly
5-78
12. Remove rod from holding fixture. Remove cylinder head
(13) and washer ring (7) from rod.
13. Remove and discard wiper seal (11), rod seal (12), wear
ring (8), back-up ring (9), and O-ring (10).
Figure 5-69. Cylinder Head Disassembly
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.
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