JLG 120HX Service Manual - Manual (Page 69)

SECTION 2 - PROCEDURES
3120819 – JLG Lift – 2-47
5. Insert dowel pins (17), spring retainer (16) and
springs (5 and 6) in housing. Insert the springs as
shown in Figure 2-23., Spring Loading.
NOTE: Be sure to use the same number of springs and
spring pattern as recorded during disassembly.
6. Position new large diameter return plate (8) in hous-
ing with tabs guided by dowel pins until disc rests
on springs.
NOTE: Discs (8 and 23) and friction discs (22) should
remain dry during installation. No oil residue should
be allowed to contaminate disc surfaces.
7. Place a new friction disc (22) on shaft until it con-
tacts return plate.
8. Add additional new discs (23) and new friction discs
as required to complete assembly.
9. Insert separator assemblies (9 and 10) in holes of
return plate.
10. Install new o-ring (19), new back-up ring (18), new o-
ring (21) and new back-up ring (20) on piston (24).
Note order of o-rings and back-up rings. Insert pis-
ton into end cover (13), being careful not to shear o-
rings or back-up rings.
11. Install new case seal (11) in housing, then install
bleeder screw (14), gasket (27) and o-ring (26) in
end cover.
12. Position end cover on housing, aligning dowel pins
with holes in end cover.
13. Install washer head bolts (12) and tighten evenly to
draw end cover to housing. Torque washer head
bolts to 75 Nm (55 ft. lb.).
NOTE: If available, a hydraulic press will simplify installation
of end cover on housing. Clamp cover in position
while tightening the washer head bolts.
14. If hydrostatic bench testing is performed on the
brake assembly, release pressure should not
exceed 138 bar (2,000 psi) unless two additional
bolts are used for supplemental clamping.
2.22 FREE WHEELING OPTION
To Disengage Drive Motors and Brakes (Free
Wheel) for Towing, etc
1. Chock wheels securely if not on flat level surface.
2. Disconnect both drive hubs by inverting disconnect
caps in center of hubs.
3. If equipped, move steer/tow selector valve to float
(tow) position by pulling valve knob out.
To Engage Drive Motors and Brakes (Normal
Operation)
1. If equipped, move steer/tow selector valve to steer
position by pushing valve knob in.
2. Connect both drive hubs by inverting disconnect
cap in center of hub.
3. Remove chocks from wheels as required.
Figure 2-23. Spring Loading