JLG 4394RT Service Manual - Manual (Page 173)

SECTION 4 - HYDRAULICS
3121249 – JLG Lift – 4-7
12. Tighten the capscrews evenly and progressively in
rotation to the specified torque value.
13. After the screws have been torqued, tap the tapered
bushing with a hammer (16 to 24 oz.) and brass
shaft (approximately 3/4" in diameter) as follows;
a. Place the shaft against the cylinder rod and in
contact with the bushing in the spaces between
the capscrews.
b. Tap each space once; this means the tapered
bushing is tapped 3 times as there are 3 spaces
between the capscrews.
14. Re-torque the capscrews evenly and progressively
in rotation to the specified torque value.
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 4-11.)
17. 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.
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 4-2, Holding Valve Torque
Specifications).
23. 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.
Figure 4-12. Tapered Bushing Installation
Figure 4-13. Seating the Tapered Bearing
Figure 4-14. Rod Assembly Installation