JLG 3394RT Service Maintenance Manual page 132

SECTION 4 - HYDRAULICS
9. Place new guide locks and seals in the applicable
outside diameter grooves of the cylinder piston.
(See Figure 4-11.)
10. Position the cylinder barrel in a suitable holding fix-
ture.
NOTICE
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.
11. 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.
12. Continue pushing the rod into the barrel until the cyl-
inder head gland can be inserted into the barrel cyl-
inder.
13. Secure the cylinder head gland using the washer
ring and socket head bolts.
Figure 4-14. Rod Assembly Installation
14. 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.
15. If applicable, install the cartridge-type holding valve
and fittings in the rod port block, using new o-rings
as applicable. (See Table 4-2, Holding Valve Torque
Specifications).
4-8
Table 4-1. Cylinder Piston Nut Torque Specifications
Description
Lift Cylinder
Lockout Cylinder
Steer Cylinder
Table 4-2. Holding Valve Torque Specifications
Description
Sun - 7/8 hex M20 x 1.5 thds
Sun - 1-1/8 hex 1 - 14 UNS thds
Sun - 1-1/4 hex M36 x 2 thds
Racine - 1-1/8 hex 1-1/16 - 12 thds
Racine - 1-3/8 hex 1-3/16 - 12 thds
Racine - 1-7/8 hex 1-5/8 - 12 thds
16. Push the piston onto the rod until it abuts the spacer
end and install the attaching nut.
WHEN REBUILDING THE CYLINDERS, APPLY LOCTITE #242 TO
PISTON NUT AND SETSCREW, THEN TORQUE PISTON NUT.
REFER TO TABLE 4-1, CYLINDER PISTON NUT TORQUE SPECIFI-
CATIONS
NOTE: The Steer Cylinder uses snap rings to secure piston.
17. Prior to setscrew installation spot drill rod before
installing the setscrew(s) which secure the piston
attaching nut to the diameter groove.
18. Remove the cylinder rod from the holding fixture.
19. Position the cylinder barrel in a suitable holding fix-
ture.
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.
– JLG Lift –
Nut Torque Setscrew
Value torque Value
400 ft lb 100 in lb
(542 Nm) (12 Nm)
N/A N/A
N/A N/A
Torque Value
30 - 35 ft lb 41 - 48 Nm
45 - 50 ft lb 61 - 68 Nm
150 - 153 ft lb 204 - 207 Nm
50 - 55 ft lb 68 - 75 Nm
75 - 80 ft lb 102 - 109 Nm
100 - 110 ft lb 136 - 149 Nm
NOTICE
3121133