JLG 660SJ Service Manual - Manual (Page 143)

SECTION 5 - HYDRAULICS
3120840 – JLG Lift – 5-11
Main Boom Lift Cylinder Installation
1. Install lift cylinder in place using suitable slings or
supports, aligning attach pin mounting holes on the
turntable.
2. Using a suitable drift, drive the barrel end attach pin
through the mounting holes in the lift cylinder and
the turntable. Secure in place with the pin retaining
hardware.
3. Remove cylinder port plugs and hydraulic line caps
and correctly attach lines to cylinder ports.
4. Using auxiliary power, extend the cylinder rod until
the attach pin hole aligns with those in the boom.
Using a suitable soft mallet, drive the cylinder rod
attach pin through the boom and lift cylinder. Secure
the pin in place with attaching hardware.
5. Remove boom prop and overhead crane. Activate
hydraulic system.
6. Using all applicable safety precautions, operate the
boom functions. Check for correct operation and
hydraulic leaks. Secure as necessary.
7. Check fluid level of hydraulic tank and adjust as nec-
essary.
5.5 CYLINDER REMOVAL AND
INSTALLATION (A MODELS)
Main Boom Telescope Cylinder Removal
1. Place machine on a flat and level surface, with main
boom in the horizontal position. Extend telescope
up to gain to pin #1.
2. Shut down engine. Support main boom basket end
with a prop (See Figure 5-19., Boom Positioning and
Support, Cylinder Repair (A Models).
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.
Figure 5-15. Location of Components - Telescope and Lift Cylinder