JLG 450AJ Service Manual - Manual (Page 23)

SECTION 2 - PROCEDURES
3120869 – JLG Lift – 2-7
13. Install wear pads at end of base boom section.
Using shims, adjust the adjustable wear pads to
zero clearance. Adjust pads alternately side to side,
so that fly boom section is centered in base boom
section.
14. Retract boom section fully. Using shims, adjust wear
pads at aft end of boom section to zero clearance.
Adjust pads alternately side to side, so that fly boom
section is centered in base boom section.
15. Disconnect auxiliary power source from telescope
cylinder.
Installation of the Boom Assembly
1. Using suitable lifting equipment, position boom
assembly on turntable so that boom pivot holes in
both boom and turntable are aligned.
2. Install boom pivot pin, ensuring that location of the
hole in pivot pin aligns with attach point on upright.
3. Using all applicable safety precautions, operate lift-
ing equipment in order to position boom lift cylinder
and level link so that holes in cylinder rod end and
level link are aligned with the one in the turntable.
Insert cylinder pins.
4. If necessary, gently tap pins into position with a soft
headed mallet, ensuring that attach holes in pins are
aligned with attach holes in boom structure. Secure
with hardware.
5. Connect all hosing and wiring.
6. Install the platform to the boom assembly.
7. Connect all hosing and wiring at platform control
station.
8. Using all safety precautions, operate machine sys-
tems and extend and retract boom for four or five
cycles.
9. Shut down machine systems and check for leakage.
2.7 DRIFT TEST
NOTE: It is recommended that the machine be shut down in
the test mode for at least one hour prior to beginning
the drift test. This will allow the oil temperature in the
cylinder to stabilize with the ambient temperature.
Thermal expansion or retraction of the hydraulic oil
can greatly affect cylinder movement.
Telescope Cylinder
NOTE: Switches referenced in this procedure are located on
the Ground Control Panel.
1. Activate hydraulic system, properly set extendable
axles and position boom in stowed position; adhere
to all safety precautions.
BEFORE RAISING AND EXTENDING BOOM, ENSURE THAT
AREAS ABOVE AND BELOW BOOM AND PLATFORM AND AHEAD
OF PLATFORM ARE CLEAR OF ALL OBSTRUCTIONS AND PER-
SONNEL.
2. Position LIFT control switch to UP and hold until
boom reaches horizontal.
3. Position TELESCOPE control switch to OUT and
hold until boom extends approximately 1.2 meters
(4 feet); measure from end of base section to end of
mid section.
4. Position LIFT control switch to UP and hold until
boom reaches maximum elevation. Shut down
engine.
5. Tag and carefully disconnect the hydraulic lines to
the telescope cylinder at control valve.
6. Observe oil flow from cylinder lines. Oil leaking from
extend port hose indicates a leaking counterbalance
valve. Oil leaking from retract port hose indicates
leakage by cylinder piston.
7. Leave boom elevated in test position for approxi-
mately one hour.
BEFORE LOWERING BOOM, ENSURE THAT AREAS BELOW
BOOM AND PLATFORM ARE CLEAR OF ALL PERSONNEL AND
OBSTRUCTIONS.