JLG M450 ANSI Service Manual - Manual (Page 118)

SECTION 4 - BOOM & PLATFORM
4-6 – JLG Lift – 3121127
4.5 UPPER BOOM TELESCOPE CYLINDER
Removal
1. Place machine on flat and level surface, with Upper
Boom in the horizontal position. Extend Upper
Boom until fly attach pin #1 is accessible on fly.
2. Support Upper Boom basket end with a prop. Sup-
port Upper Upright end with an overhead crane.
3. Tag, disconnect hydraulic lines to telescope cylinder.
Use suitable container to retain any residual hydrau-
lic fluid. Cap hydraulic lines and ports.
4. Remove the retaining rings that retain the telescope
cylinder rod to the fly boom.
5. Using a suitable brass drift, carefully drive the tele-
scope cylinder rod pin #1 from the fly boom.
6. Remove the four (4) bolts securing the telescope
cylinder barrel end to the base boom.
NOTE: Care should be taken when removing the telescope
cylinder, do not leave cylinder rest on powertrack
which could cause damage to powertrack.
7. Using a suitable brass drift, carefully drive the tele-
scope cylinder pin from the base boom.
8. Attach a suitable sling to the telescope cylinder.
Using a suitable lifting device attached to the sling
carefully pull the telescope cylinder from the boom
assembly.
9. Using another lifting device, support the rod end of
the cylinder and remove the cylinder from the boom
assembly.
10. Carefully lift the cylinder clear of the boom assembly
and lower to the ground or suitably supported work
area.
Installation
1. Attach a hydraulic power supply to the telescope
cylinder ports. Using suitable supports or lifting
devices at each end of the cylinder, extend the rod
so that the cylinder pin attach holes are the same
distance apart as the boom pin attach holes.
2. Using suitable lifting equipment, carefully lower the
cylinder to the boom assembly.
3. Using another lifting device, support the rod end of
the cylinder and install the cylinder into the boom
assembly.
4. Remove lifting devices from the telescope cylinder.
5. Carefully install the telescope cylinder rod pin #1
through the fly boom and secure it with the retaining
rings.
6. Carefully install the telescope cylinder barrel end to
base, securing cylinder to the base boom with four
(4) bolts and hardware.
7. Remove applicable hydraulic line and port caps and
correctly connect the hydraulic lines to the tele-
scope cylinder. Ensure all hoses are correctly
routed.
8. Remove boom prop and overhead crane. Activate
hydraulic system.
9. Using all applicable safety precautions, operate the
boom functions. Check for correct operation and
hydraulic leaks. Secure as necessary.
10. Check fluid level of hydraulic tank and add as neces-
sary.
Figure 4-5. Upper Telescope Cylinder Removal