JLG 450AJ Service Manual - Manual (Page 21)

SECTION 2 - PROCEDURES
3120869 – JLG Lift – 2-5
2. Remove the boom from the turntable as follows:
a. Disconnect wiring harness from ground control
harness connector.
HYDRAULIC LINES AND PORTS SHOULD BE CAPPED IMMEDI-
ATELY AFTER DISCONNECTING LINES TO AVOID ENTRY OF
CONTAMINANTS INTO SYSTEM.
b. Tag and disconnect hydraulic lines from boom
to control valve. Use a suitable container to
retain any residual hydraulic fluid. Cap all
hydraulic lines and ports.
c. Using a suitable lifting equipment, adequately
support boom weight along entire length.
d. Remove the bolts and keeper pins securing the
lift cylinder pivot pin. Using a suitable brass drift
and hammer, remove the pivot pin from the
lower boom.
NOTE: To gain access for removal of the pivot pins, it may
be necessary to remove the ground control box,
hydraulic and fuel tanks, and the counterweight.
e. Remove hardware securing the level link pivot
pin. Using a suitable brass drift and hammer,
remove the pin from the level link and turntable.
f. Remove hardware securing the lower boom
pivot pin. Using a suitable brass drift and ham-
mer, remove pin from the turntable.
g. Using all applicable safety precautions, carefully
lift boom assembly clear of turntable and lower
to ground or suitable supported work surface.
Disassembly of the Main Boom
1. Loosen jam nuts on aft end of fly boom wear pad
adjustment and loosen adjustments.
2. Using a portable power source, attach hose to tele-
scope cylinder port block. Using all applicable
safety precautions, activate hydraulic system and
extend cylinder to gain access to cylinder rod retain-
ing pin. Shut down hydraulic system.
3. Carefully disconnect hydraulic hose from retract port
of cylinder. There will be initial weeping of hydraulic
fluid which can be caught in a suitable container.
After initial discharge, there should be no further
leakage from the retract port.
4. Remove hardware securing telescope cylinder to
the fly boom section, then remove pin from fly.
5. Remove hardware securing telescope cylinder to
the base boom section.
WHEN REMOVING TELESCOPE CYLINDER FROM BOOM SEC-
TIONS. CARE SHOULD BE TAKEN NOT TO LEAVE CYLINDER
REST ON POWERTRACK WHICH COULD CAUSE DAMAGE TO
POWERTRACK.
RETAINING RING
RETAINING RING
BASE BOOM
FLY BOOM
TELESCOPE CYLINDER
Figure 2-2. Location of Components - Removal of Telescope Cylinder