JLG E45A_AJ ANSI Service Manual - Manual (Page 48)

SECTION 2 - PROCEDURES
2-32 – JLG Lift – 3120765
2.15 MID AND LOWER LIFT CYLINDER
BLEEDING PROCEDURE
NOTE: Bleeding procedure should only be necessary if
rebuilding or replacing lift cylinder.
1. Check oil level in the hydraulic oil tank (all booms
must be retracted).
2. Lay an oil drip pan under the rod end port block
(Mid Cylinder) and crack bleeder open from the fit-
ting in the port block.
3. From the platform, turn the speed control knob to
the slow position.
4. Lift up very slowly. This will force any air out of the
circuit. If the lower boom is not extending, turn the
speed control up very slowly until the lower boom
starts to move.
5. Raise the lower boom approx. 1 foot (30.5 cm), then
close bleeder while the boom is still moving.
6. Lift down all the way.
7. Repeat this procedure until all air has been purged
from the circuit. Re-check the hydraulic oil level.
8. To test, cycle the lower lift function 3-4 times to see if
both cylinders stop at the same time when fully
extended.
2.16 BOOM SYNCHRONIZING PROCEDURE
NOTE: If the Lower Boom assembly does not fully lower:
1. Remove all personnel from the platform.
2. Pull the red knob located under the main control
valve.
3. From Ground Control, activate the lift control switch,
raise Lower Boom 6 feet (1.8m).
4. After raising Lower Boom, release the red knob.
5. Activate Lower Boom Down, fully lower boom.
6. Repeat step 1 thru 5 if necessary.
2.17 DRIVE HUB
Setting of Tapered Roller Bearings
NOTE: The numbers in parentheses ( ) reference the figure
Drive Hub- Cutaway.
1. De-grease threads of the spindle (60) and shaft nut
(4).
2. Spin the shaft nut onto spindle by hand to insure the
threads are in good condition.
3. Apply Loctite 270 evenly to threads of the shaft nut.
4. Rotate the support ring repeatedly in one direction
only, during setting of the tapered roller bearings.
5. Tighten shaft nut to 626 ft. lbs. (850 Nm).
6. Do not use the hub for 24 hours to allow the Loctite
to harden properly.
7. Do not fill with oil for 24 hours to allow the Loctite to
harden properly.
Securing of the Shaft Nut
1. After proper bearing setting is completed, use a suit-
able punch to place ball (24) 0.04 to 0.05 inches (1.1
to 1.3 mm) into the spindle thread. Then set ball (24)
in position by punching in expander (25).