JLG 400CRT ANSI Service Manual - Manual (Page 27)

SECTION 2 - PROCEDURES
3121111 – JLG Lift – 2-13
15. Remove the cylinder rod from the holding fixture.
16. Place new guide locks and seals in the applicable
outside diameter grooves of the cylinder piston.
(See Figure 2-11., Piston Seal Kit Installation)
17. Position the cylinder barrel in a suitable holding fix-
ture.
IMPORTANT
EXTREME CARE SHOULD BE TAKEN WHEN INSTALLING THE
CYLINDER 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 2-1, Cylinder Component
Torque).
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.
23. If applicable, install the cartridge-type holding valve
and fittings in the port block using new o-rings as
applicable. (SeeTable 2-2, Holding Valve Torque
Specifications).
Figure 2-14. Poly-Pak Piston Seal Installation
Figure 2-15. Rod Assembly Installation
Table 2-1. Cylinder Component Torque
Component
Torque Value
(w/Loctite)
Tapered Bushing Retaining Screws - Lift Cylinder 80 ft lb
(108 Nm)
Head Retaining Screws - Lift Cylinder 9 ft lb
(12 Nm)
Table 2-2. Holding Valve Torque Specifications
Description Torque Value
Sun - 7/8 hex M20 x 1.5 thds 30 - 35 ft lb 41 - 48 Nm
Sun - 1-1/8 hex 1 - 14 UNS thds 45 - 50 ft lb 61 - 68 Nm
Sun - 1-1/4 hex M36 x 2 thds 150 - 153 ft lb 204 - 207 Nm
Racine - 1-1/8 hex 1-1/16 - 12 thds 50 - 55 ft lb 68 - 75 Nm
Racine - 1-3/8 hex 1-3/16 - 12 thds 75 - 80 ft lb 102 - 109 Nm
Racine - 1-7/8 hex 1-5/8 - 12 thds 100 - 110 ft lb 136 - 149 Nm