JLG 450A II Series, Service And Maintenance Manual

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SECTION 3 - CHASSIS & TURNTABLE
3121290 – JLG Lift – 3-35
3.5 ADJUSTMENT PROCEDURE FOR LOCKOUT VALVE
1. With turntable centered, adjust bracket with washers to
push plunger in 5/16" ± 1/16" (7.9 ± 1.6 mm).
2. Ideal adjustment is 3/8" (9.5 mm). Do not push plunger
in more than 3/8" (9.5 mm). The extra adjustment is
needed for turntable bearing play.
3.6 OSCILLATING AXLE BLEEDING PROCEDURE AND
LOCKOUT TEST
FULLY LOWER PLATFORM AND CENTER BOOM OVER REAR AXLE BEFORE
STARTING BLEEDING PROCEDURE.
ENSURE MACHINE IS ON A LEVEL SURFACE AND REAR WHEELS ARE BLOCKED,
AND BRAKE WIRE IS DISCONNECTED.
Lockout Cylinder Bleeding (Ram Cylinders)
1. Position turntable to normal stowed position so axle is
free to oscillate. Drive charge pressure will pass through
lockout valve built into swivel and down to pilot section
of holding valves on cylinders. This will automatically
purge air from pilot section of circuit.
2. Attach end of clear tubing to bleeder valve nipple and
place other end in container to catch oil. Using a 3/8"
wrench, slowly turn bleeder valve counter-clockwise to
bleed air from cylinder. Have operator in platform just
crack drive controller in reverse. This will activate brake
valve sending charge pressure to lockout cylinder. Close
valve when an unbroken, steady stream of oil is seen.
3. Repeat procedure for other lockout cylinder.
1. Washer
2. Bracket
3. Lockout Valve
Figure 3-30. Valve Adjustment