JLG 1850SJ Service Manual - Manual (Page 221)

SECTION 5 - BASIC HYDRAULIC INFORMATION & HYDRAULIC SCHEMATICS
3121619 – JLG Lift – 5-51
ASSEMBLY
NOTE: Use proper cylinder seal kit for cylinder assembly. See your
JLG Parts Manual.
Apply a light film of hydraulic oil to all components before
assembly.
IMPROPER SEAL INSTALLATION CAN CAUSE CYLINDER LEAKS AND IMPROPER
CYLINDER OPERATION.
1. Install new wear ring (16) in cylinder head (13).
2. Install seal (12) and wiper (11) in cylinder head.
3. Install backup ring (14) and O-ring (15) in outside diame-
ter grooves of cylinder head.
4. Install cylinder head assembly on rod. Do not damage or
dislodge wiper and rod seals. Push head along rod to
rod end.
5. Install O-ring (18) in spacer (17). Slide spacer on rod.
6. Install O-ring (19) to inside groove of piston (20).
7. Install seal (22) and two wear rings in outer grooves of
piston.
8. Using suitable protection, clamp cylinder rod in a vise or
similar holding fixture as close to piston as possible.
9. Apply medium-strength locking compound JLG P/N
0100011or equivalent to rod threads.
10. Install piston on cylinder rod. Do not damage or dis-
lodge O-ring. Torque to 100 ft-lb (135 Nm).
11. Remove cylinder rod from holding fixture.
12. Position cylinder barrel in a suitable holding fixture.
INSERTING ROD OFF-CENTER CAN DAMAGE PISTON AND CYLINDER BARREL
SURFACES. USE EXTREME CARE WHEN INSTALLING C YLINDER ROD, HEAD,
AND PISTON.
13. Clamp barrel securely and support rod. Insert piston end
into barrel cylinder. Do not damage or dislodge piston
O-rings and seals.
14. Continue pushing rod into barrel until cylinder head
gland can be inserted into barrel cylinder.
12
11
13
14
16
15
Figure 5-90. Cylinder Head Assembly
17
18
19
20
21
22
21
Figure 5-91. Piston and Spacer Assembly