JLG 800A_AJ ANSI Service Manual - Manual (Page 304)

SECTION 5 - HYDRAULICS
5-24 – JLG Lift – 3120740
5.7 CYLINDER REMOVAL AND
INSTALLATION
Upper Boom Telescope Cylinder Removal
1. Place machine on a flat and level surface, with upper
boom in the horizontal position. Extend telescope
up to gain access to main fly boom telescope cylin-
der, rod end pin #1.
2. Shut down engine. Support upper boom platform
end with a crane of adequate capacity.
HYDRAULIC LINES AND PORTS SHOULD BE CAPPED IMMEDI-
ATELY AFTER DISCONNECTING LINES TO AVOID THE ENTRY OF
CONTAMINANTS INTO THE SYSTEM
3. Tag and disconnect hydraulic lines to telescope cyl-
inder. Use suitable container to retain any residual
hydraulic 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 telescope
cylinder rod pin from the fly boom.
6. Remove mounting hardware securing the Upper Lift
Cylinder rod end to the base boom.
7. Using a suitable brass drift, carefully drive upper lift-
cylinder rod end pin from the base boom.
8. Use the auxiliary control to retract the upper lift cylin-
der.
9. Remove mounting hardware securing the upper
boom telescope cylinder, barrel end to the main
base boom.
10. Attach a suitable sling to the telescope cylinder.
Using a suitable lifting device attached to the sling,
carefully pull the cylinder partially from the front end
of boom assembly (thru tower upright upper access
hole).
11. Secure the cylinder with a suitable sling and lifting
device at the approximate center of gravity.
12. Carefully lift the cylinder clear of the boom assembly
and lower to the ground or suitably supported work
area.
Figure 5-24. Components Upper Boom and Tower Boom