JLG 510AJ Service Manual - Manual (Page 230)

SECTION 5 - HYDRAULICS AND HYDRAULIC SCHEMATICS
5-10 – JLG Lift – 3121181
7. Using suitable protection, clamp cylinder rod (20) in a
vise or similar holding fixture near piston.
8. Remove retaining ring (19) and nut (18).
9. Unscrew and remove piston assembly (16).
10. Remove O-Ring (15) and seal (17) from piston.
11. Remove spacer (14) from rod.
12. Remove O-Ring (13) from spacer.
Figure 5-16. Piston And Spacer Disassembly
13. Remove head assembly (8) from rod.
14. Remove O-Ring (10), backup ring (9), and O-Ring (12)
from cylinder head.
15. Remove O-Ring (4) and retaining ring (5), wiper (6), and
seal (7) from front inside of cylinder head.
16. Remove three wear rings (11) from rear inside of cylin-
der head.
Figure 5-17. Cylinder Head Disassembly
CLEANING AND INSPECTION
1. Clean all parts with approved cleaning solvent.
2. Inspect cylinder rod for scoring, tapering, ovality, or
other damage. Dress rod with Scotch Brite or equivalent.
Replace rod if necessary.
3. Inspect threaded portion of rod for 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, and distor-
tion. Dress piston surface or replace piston.
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, ovality, and tapering. Replace as needed.
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 surfaces as necessary.
12. Inspect cylinder head outside diameter for scoring or
other damage, ovality, and tapering. Replace as needed.
13. Inspect rod and barrel bushings.
a. Remove burrs, dirt, or other contamination.
b. Inspect for wear or damage. If steel bushing is worn
or damaged, rod/barrel must be replaced.
c. Lubricate inside of steel bushing with WD40 before
installing composite bushings. Install new bushings
using an arbor.
NOTE: Lubrication is not required with nickel plated pins and
bearings. Install pin in composite bushing dry.
Figure 5-18. Composite Bushing Installation
14. Inspect oil ports for blockage or presence of dirt or other
foreign material. Clean or repair as needed.
19
18
16
17
15
14
13
10
9
11
7
12
6
5
4 Arbor
Barrel or
Rod Bushing
Composite
Bushing
Composite
Bushing