JLG 450A_AJ Series II Service Manual - Manual (Page 315)

SECTION 5 - HYDRAULICS
3121180 – JLG Lift – 5-25
11. Remove cylinder rod from holding fixture.
12. Place new guide locks and seals in applicable out-
side diameter grooves of cylinder piston. (See Fig-
ure 2-28. Piston Seal Kit Installation.)
13. Position cylinder barrel in a suitable holding fixture.
EXTREME CARE SHOULD BE TAKEN WHEN INSTALLING CYLIN-
DER ROD, HEAD, AND PISTON. AVOID PULLING THE ROD OFF-
CENTER, WHICH CAN DAMAGE PISTON AND CYLINDER BARREL
SURFACES.
14. With barrel clamped securely, and while adequately
supporting rod, insert piston end into barrel cylinder.
Ensure piston loading O-ring and seal ring are not
damaged or dislodged.
15. Continue pushing rod into barrel until cylinder head
gland can be inserted into barrel cylinder.
16. Secure cylinder head gland using washer ring and
socket head bolts. (See Table 2-1 and 2-3. Torque
Specifications.)
17. After cylinder has been reassembled, rod should be
pushed all the way in (fully retracted) before reinstal-
lation of any holding valve or valves.
18. If applicable, install cartridge-type holding valve and fit-
tings in rod port block. Use new O-rings as applicable.
(See Table 2-2. Holding Valve Torque Specifications).
Table 5-1. Cylinder Head and Tapered Bushing Torque
Specifications
Description
Head Torque
Value (Wet)
Tapered Bushing
Torque Value
(Wet)
Lift Cylinder 120 ft. lbs.
(163 Nm)
9 ft. lbs.
(12 Nm)
Figure 5-32. Rod Assembly Installation
Slave Cylinder 30 ft. lbs.
(41 Nm)
5 ft. lbs.
(9 Nm)
Master Cylinder 30 ft. lbs.
(41 Nm)
5 ft. lbs.
(9 Nm)
Jib Cylinder 30 ft. lbs.
(41 Nm)
5 ft. lbs.
(9 Nm)
Lockout Cylinder 80 ft. lbs.
(109 Nm)
N/A
Steer Cylinder Piston Nut Torque Specifications
Steer Cylinder LBS. NM
150 ft. lbs 204 Nm
Table 5-2. Holding Valve Torque Specifications
Description Torque Value
SUN - 7/8 HEX M20 X 1.5 THDS. 30-35 ft. lbs.
(41-48 Nm)
SUN - 1 1/8 HEX 1 -14 UNS THDS. 45-50 ft. lbs.
(61-68 Nm)
SUN - 1 1/4 HEX M36 X 2 THDS. 150-160 ft. lbs.
(204-217 Nm)
RACINE - 1 1/8 HEX 1 1/16 - 12 THDS. 50-55 ft. lbs.
(68-75 Nm)
RACINE - 1 3/8 HEX 1 3/16 - 12 THDS. 75-80 ft. lbs.
(102-109 Nm)
RACINE - 1 7/8 HEX 1 5/8 - 12 THDS. 100-110 ft. lbs.
(136-149 Nm)
Table 5-1. Cylinder Head and Tapered Bushing Torque
Specifications
Description
Head Torque
Value (Wet)
Tapered Bushing
Torque Value
(Wet)