JLG 740A, Service And Maintenance Manual

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SECTION 3 - CHASSIS & TURNTABLE
3121160 – JLG Lift – 3-159
3. Run compressor and test for leaks.
Coalescer (Air/Oil Separator) Replacement
This is a spin-on, throw away type unit. Before attempting
to change ensure all pressure is relieved from the system.
Change in accordance with Maintenance Guidelines. If oil
carryover into the service line occurs and the oil scavenge
return line scavenge shows little or no oil return, then
change the element. Verify receiver is not over full.
USE ONLY ORIGINAL EQUIPMENT COALESCER ELEMENT TO
ENSURE PRESSURE RATING AND PERFORMANCE IS SATISFAC-
TORY.
REMOVAL:
1. Remove old element (use strap wrench if required)
by turning anti-clockwise and discard as appropriate
and in accordance with any pertinent regulations.
REPLACEMENT:
1. Apply a light film of oil to the seal surface on the new
element.
2. Screw element on clockwise until it seats on the
head, rotate an additional 3/4 turn (by hand). Take
care not to damage element.
3. Start up and check for leaks.
Air Filter Replacement
DO NOT replace with compressor in operation. If environ-
ment is dirty or dusty an earlier change out may be
required. To ensure correct filtration use only original
equipment filters.
REMOVAL:
1. Unscrew the wing nut on top of the air filter and
remove filter cover.
2. Discard filter as appropriate and in accordance with
any pertinent regulations.
REPLACEMENT:
1. Clean cover and any dirt inside filter housing taking
extreme care that no dust/dirt particles reach the air
intake of the compressor.
2. Fit new element inside housing.
3. Replace lid and tighten wing nut on top of air filter
assembly.
4. Test run and functional test.
Belts - Tightening and Replacement
Correct tensioning and alignment is important for belt life,
bearing life and power transmission.
Correct tensioning and alignment was provided at time of
shipment from the factory. However, since maximum belt
elongation will occur within the first 50 hours of operation
(Of new belts), their tension should be checked several
times during this period and corrected as required. The
belts should thereafter be checked periodically in order to
obtain maximum life and performance.
NOTE: To avoid possible belt damage, never force belts over
the sheaves. Oil spilled or splashed onto the belts in
any quantity will cause slippage and severely reduce
belt life - take care when filling compressor oil.
REPLACING/TIGHTENING V-BELTS:
1. Loosen slightly the bolt at the base of the hydraulic
motor mounting bracket. This will allow the hydraulic
motor to be moved in or out to tighten or loosen the
belts.
2. Back off adjusting bolt lock nut. Screw the adjusting
bolt clockwise to tighten belt or anti clockwise to
loosen belts.
3. After adjustments have been made, tighten base
bolt to insure no further movement.
TENSION DATA
Deflection at center of belt span 0.25 inches (6.35 mm),
with a force of 4 pounds (1.8 kg).
Pulley alignment is set at factory and shouldn’t need to be
adjusted, if it is found necessary to adjust the pulley align-
ment, this
is done by loosening the four bolts that hold
down the base plate to the frame and adjust per following
instructions.
Ensure pulleys are aligned by using a long straight edge
which will span both pulleys. Position the straight edge on
the sides of the pulleys, if they are in-line there should be
no gaps between the straight edge and the pulleys (for the
full contact distance across each pulley side), adjust as
necessary to get correct alignment and tension.
It may be necessary to repeat and check several times
before both tension and alignment are satisfied.