JLG 660SJ ANSI Service Manual - Manual (Page 178)

SECTION 5 - HYDRAULICS
5-12 – JLG Lift – 3120718
Main Boom Lift Cylinder Removal
1. Place the machine on a flat and level surface. Start
the engine and place the main boom in the horizon-
tal position. Shut down engine and prop the boom.
(See Figure 5-18., Boom Positioning and Support,
Cylinder Repair (A Models).
2. Remove the hardware retaining the cylinder rod
attach pin #2 to the boom. Using a suitable brass
drift, drive out the cylinder rod attach pin.
3. Using auxiliary power, retract the lift cylinder rod
completely.
4. Disconnect, cap and tag the main boom lift cylinder
hydraulic lines and ports.
5. Remove barrel end attach pin #3 retaining hard-
ware. Using a suitable brass drift drive out the barrel
end attach pin from the upright.
6. Remove the cylinder from the boom and place in a
suitable work area.
Main Boom Lift Cylinder Installation
1. Install lift cylinder in place using suitable slings or
supports, aligning attach pin mounting holes on the
upright.
2. Using a suitable drift, drive barrel end attach pin #3
through the mounting holes in the lift cylinder and
the upright. 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 drift drive cylinder rod attach pin #2
through the aligned holes, taking care to align the
grooved pin holes. 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.
Figure 5-16. Leveling Cylinder Removal