JLG 600A_AJ Service Manual - Manual (Page 226)

SECTION 5 - HYDRAULICS
5-16 – JLG Lift – 3121201
Tower Lift Cylinder Installation
1. With the main boom and tower boom positioned
and supported as in Figure 5-17., Boom Positioning
and Support, Cylinder Repair, place the tower lift cyl-
inder in position on the turntable and secure in place
using slings.
2. Align holes in turntable and lift cylinder. Using a suit-
able rubber mallet, install the cylinder barrel pin and
secure with mounting hardware.
3. Connect an auxiliary power source to the cylinder
and extend cylinder rod until the cylinder rod bush-
ing aligns with bushings on boom.
4. Using an appropriate brass drift, drive the rod attach
pin through the aligned bushings. Secure pin with
attaching hardware.
5. Remove caps from cylinder hydraulic lines and cor-
rectly install lines to cylinder as previously tagged.
6. Remove boom prop and overhead crane. Activate
hydraulic system.
7. Using all applicable safety precautions, operate the
boom functions. Check for correct operation and
hydraulic leaks. Secure as necessary.
8. Check fluid level of hydraulic tank and adjust as nec-
essary.
Tower Telescope Cylinder Removal
1. Place machine on a flat and level surface, with main
boom in the horizontal position. Shut down engine
and prop the boom See Figure 5-18., Tower Tele-
scope Cylinder Removal.
2. With the aid of an assistant, manually override the
Plunger Valve with a pry bar, and from Ground Con-
trol, using auxiliary power, extend the tower tele-
scope out to gain access to fly attach pin.
3. Remove lower cover plate.
4. Remove mounting hardware securing powertrack to
tower boom assembly. After removing mounting
hardware, slide powertrack backward far enough to
move holes and wiring harness to the side to gain
access to telescope cylinder.
5. Tag, disconnect and cap hydraulic hoses to Tower
Telescope Cylinder. Plug cylinder ports.
6. Remove mounting hardware securing upper cylin-
der pin to fly boom. Using a suitable brass drift, drive
out the cylinder rod pin.
7. Remove mounting hardware attaching retaining
plates to base boom and remove plate.
8. Carefully slide the telescope cylinder from the
boom. Place cylinder on a suitable work area.
Tower Telescope Cylinder Installation
1. With the boom positioned as in Figure 5-18., Tower
Telescope Cylinder Removal, slide the telescope cyl-
inder into the boom, aligning the cylinder port block
end with slotted holes in Base Boom. Secure tele-
scope cylinder with mounting hardware.
2. Remove caps and plugs from hydraulic lines and
ports. Properly connect hydraulic lines to cylinder as
tagged during Removal. Reinstall cover plate.
3. Start engine. With the aid of an assistant, manually
override the plunger valve. Activate Tower telescope
out to align attaching pin holes in Fly Boom. Shut
down engine.
4. Using a brass drift, drive in the attach pin. Secure in
place with mounting hardware.
5. Align holes in base boom and powertrack. Secure
the powertrack with mounting hardware.
6. Remove boom prop and overhead crane. Activate
hydraulic system.
7. Using all applicable safety precautions, operate the
boom functions. Check for correct operation and
hydraulic leaks. Secure as necessary.
8. Check fluid level of hydraulic tank and adjust as nec-
essary.