JLG 450AJ ANSI Service Manual - Manual (Page 45)

SECTION 2 - PROCEDURES
3120749 – JLG Lift – 2-27
2.14 JIB
Removal
1. Place the Jib in a horizontal position and support the
complete assembly with adequate blocking.
2. Remove the Platform as follows:
a. Disconnect the electrical connectors going into
the platform control box.
b. Remove the bolts, nuts, and washers connect-
ing the platform basket to the platform support.
c. Using a suitable lifting device, remove the plat-
form basket from the platform support.
3. Tag and disconnect the hydraulic lines running to
the jib. Use a suitable container to collect any resid-
ual fluid. Cap the hydraulic lines and ports.
4. Remove the hardware securing the jib pivot pin at
the boom. Using a suitable brass drift and hammer,
remove the pin from the fly boom. Use a suitable lift-
ing device and remove the jib.
2.15 BLEEDING OSCILLATION CYLINDERS
1. Drive the machine up onto a six inch (15 cm) block,
to extend an oscillation cylinder.
2. Flip the end caps on the drive hubs to disengage the
hubs. Activate the drive function to be sure the hubs
are disengaged.
3. Crack the bleeder screw at the bottom of the cylin-
der.
4. Operate the drive function until no air is coming out
of the bleeder valve.
5. Close the bleeder valve.
6. Engage the hubs and repeat steps 1 thru 5 for the
opposite side of the machine.
7. Perform the Oscillation Axle Lockout Test. If neces-
sary, bleed the cylinders again.
2.16 OSCILLATING AXLE LOCKOUT TEST
LOCKOUT SYSTEM TEST MUST BE PERFORMED QUARTERLY,
ANY TIME A SYSTEM COMPONENT IS REPLACED, OR WHEN
IMPROPER SYSTEM OPERATION IS SUSPECTED.
NOTE: Ensure boom is fully retracted, lowered, and cen-
tered between drive wheels prior to beginning lock-
out cylinder test.
1. Place a 6 inches (15 cm) high block with ascension
ramp in front of left front wheel.
2. From platform control station, start engine.
3. Place the DRIVE SPEED control switch to the LOW
position.
CHECK VALVE
BOTTOM TUBE
TOP TUBE
E.A.R. CYLINDER
GUARD
PIVOT SHAFT
ROTATE CYLINDER
PLATFORM SUPPORT
Figure 2-23. Jib