JLG M450 ANSI Service Manual - Manual (Page 161)

SECTION 5 - HYDRAULICS
3121127 – JLG Lift – 5-9
17. Position the cylinder barrel in a suitable holding fix-
ture.
EXTREME CARE SHOULD BE TAKEN WHEN INSTALLING THE CYL-
INDER ROD, HEAD, AND PISTON. AVOID PULLING THE ROD OFF-
CENTER, WHICH COULD CAUSE DAMAGE TO THE PISTON AND
CYLINDER BARREL SURFACES.
18. With barrel clamped securely, and while adequately
supporting the rod, insert the piston end into the
barrel cylinder. Ensure that the piston loading o-ring
and seal ring are not damaged or dislodged.
19. Continue pushing the rod into the barrel until the cyl-
inder head gland can be inserted into the barrel cyl-
inder.
20. Secure the cylinder head gland using the washer
ring and socket head bolts.
21. After the cylinder has been reassembled, the rod
should be pushed all the way in (fully retracted) prior
to the reinstallation of any holding valve or valves.
22. If applicable, install the cartridge-type holding valve
and fittings in the rod port block, using new o-rings
as applicable. (See Table 5-3, Holding Valve Torque
Specifications).
IF THE CYLINDER IS TO BE TESTED PRIOR TO INSTALLATION ON
THE MACHINE, EXTREME CARE SHOULD BE USED TO INSURE
THAT THE OUTER END OF THE ROD IS SUPPORTED. USE EITHER
A TRAVELING OVERHEAD HOIST, FORK-LIFT, OR OTHER MEANS
TO SUPPORT THE OVERHANGING WEIGHT OF THE EXTENDING
ROD.
Figure 5-13. Rod Assembly Installation
Table 5-1.Cylinder Head and Tapered Bushing Torque
Specifications
Description
Head Torque Value
(Wet)
Tapered Bushing
Torque Value (Wet)
Jib Cylinder 30 ft. lbs
(41 Nm)
5 ft. lbs.
(7 Nm)
Level Cylinder
(M450AJ)
30 ft. lbs
(41 Nm)
5 ft. lbs.
(7 Nm)
Master Cylinder
(M450AJ)
30 ft. lbs.
(41 Nm)
5 ft. lbs.
(7 Nm)
Table 5-2. Cylinder Piston Nut Torque Specifications)
Description
Nut Torque Valve
(Wet)
Setscrew Torque
Value (Dry)
Upper
Lift Cylinder 200 ft. lbs.
(270 Nm)
100 in. lbs.
(11 Nm)
Mid
Lift Cylinder 400 ft. lbs.
(542 Nm)
100 in. lbs.
(11 Nm)
Lower
Lift Cylinder 400 ft. lbs.
(542 Nm)
100 in. lbs.
(11 Nm)
Level Cylinder
(M450 A) 80 ft. lbs.
(108 Nm)
100 in. lbs.
(11 Nm)
Master Cylinder (M450A) 80 ft. lbs.
(108 Nm)
100 in. lbs.
(11 Nm)
Table 5-3. 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)