JLG 450A_AJ Series II Service Manual - Manual (Page 213)

SECTION 4 - BOOM & PLATFORM
3121290 – JLG Lift – 4-1
SECTION 4. BOOM & PLATFORM
4.1 BOOM MAINTENANCE
DO NOT USE A LIFTING DEVICE TO LIFT BOOMS UNLESS
HOLDING VALVES HAVE BEEN REMOVED FIRST. FAILURE
TO DO SO WILL RESULT IN SEVERE DAMAGE TO BOOM.
Remove Boom Assembly
1. Remove platform and platform support as follows:
a. Disconnect control console electrical cable.
b. Tag and disconnect rotate cylinder hydraulic lines.
Use a suitable container to retain residual hydraulic
fluid. Cap hydraulic lines and ports.
c. Use an appropriately rated overhead crane or suit-
able lifting device and nylon support straps to sup-
port the platform/support.
NOTE: Properly support cylinder when removing retaining pin
from rod end of level cylinder.
d. Remove bolts and keeper pins from retaining pins.
Remove retaining pins from platform support using
suitable brass drift and hammer.
2. Remove boom from turntable as follows:
a. Disconnect wiring harness from ground control har-
ness connector.
CAP HYDRAULIC LINES AND PORTS IMMEDIATELY AFTER DISCONNECTING
LINES TO PREVENT ENTRY OF CONTAMINANTS INTO SYSTEM.
b. Tag and disconnect boom to control valve hydraulic
lines. Use a suitable container to retain residual
hydraulic fluid. Cap all hydraulic lines and ports.
c. Support boom weight along entire length with
appropriately rated lifting equipment.
d. Remove bolts and keeper pins from lift cylinder
pivot pin. Using a suitable brass drift and hammer,
remove pivot pin from lower boom.
NOTE: To gain access for removal of pivot pins, it may be neces-
sary to remove ground control box, hydraulic and fuel
tanks, and counterweight.
e. Remove retaining hardware from level link pivot
pin. Using a suitable brass drift and hammer,
remove pin from level link and turntable.
f. Remove hardware securing lower boom pivot pin.
Using a suitable brass drift and hammer, 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.
Figure 4-1. Location of Components - Boom Removal