JLG 1850SJ Service Manual - Manual (Page 220)

SECTION 5 - BASIC HYDRAULIC INFORMATION & HYDRAULIC SCHEMATICS
5-50 – JLG Lift – 3121619
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.
14. Remove and discard O-ring (19), two wear rings (21),
and seal (22) from piston (20).
15. Remove and discard O-ring (18) from spacer (17).
16. Remove rod from holding fixture and remove cylinder
head.
17. Remove and discard wiper (11), seal (12), wear ring (16),
O-ring (15), and backup ring (14) from cylinder head
(13).
CLEANING AND INSPECTION
CLEAN PARTS THOROUGHLY WITH WATER AND A RUST PREVENTATIVE ONLY.
DO NOT USE ANY FORM OF DETERGENT OR SOAP.
1. Inspect cylinder rod for scoring, tapering, ovality, or
other damage. If necessary, dress rod with Scotch Brite
or equivalent. Replace rod if necessary.
2. Inspect threaded portion of rod for excessive damage.
Dress threads as necessary.
3. Inspect inner surface of cylinder barrel tube for scoring
or other damage. Check inside diameter for tapering or
ovality. Replace if necessary.
4. Inspect piston surface for damage, scoring, or distortion.
Dress piston surface or replace piston as necessary.
5. Inspect threaded portion of piston for damage. Dress
threads as necessary.
6. Inspect seal and O-ring grooves in piston for burrs and
sharp edges. Dress surfaces as necessary.
7. Inspect cylinder head inside diameter for scoring or
other damage, and for ovality and tapering. Replace as
necessary.
8. Inspect threaded portion of head for damage. Dress
threads as necessary.
9. Inspect seal and O-ring grooves in head for burrs and
sharp edges. Dress applicable surfaces as necessary.
10. Inspect cylinder head outside diameter for scoring,
damage, ovality, and tapering. Replace as necessary.
11. Inspect spacer for burrs and sharp edges. If necessary,
dress inside diameter surface with Scotch Brite or equiv-
alent.
12. Inspect port block fittings and cartridge valves. Replace
as necessary.
13. Inspect oil ports for blockage or presence of dirt or other
foreign material. Repair as necessary.
17
18
19
20
21
22
21
Figure 5-88. Piston and Spacer Disassembly
12
11
13
14
16
15
Figure 5-89. Cylinder Head Disassembly