JLG G6-23A Service Manual - Manual (Page 26)

Boom
3.4 G5-19A, G6-23A
3.3.1 Boom Removal
1. Remove any attachment from the quick switch
assembly.
2. Be sure there is enough room in front of the machine
to allow the boom sections to be removed. Park the
machine on a hard, level surface, fully retract the
boom, lower the boom, place the transmission
control lever in (N) NEUTRAL, engage the park
brake and shut the engine OFF.
3. Place an Do Not Operate Tag on both the ignition
key switch and the steering wheel, stating that the
machine should not be operated.
4. Remove the battery negative (-) cable from the
battery negative (-) terminal.
5. Open the engine cover. Allow the system fluids to
cool.
6. Remove the quick switch assembly. Refer to Section
3.5.4, “Quick Switch Removal.”
7. Support the front of the boom by placing a sling
behind the boom head. Support the lift/lower cylinder
and remove the lock bolt and then the rod end pin.
Lower the lift/lower cylinder onto the frame rails.
8. Label and disconnect the tilt and auxiliary hydraulic
hoses attached to the machine at the rear of the
boom. Plug and cap the hose ends to prevent dirt
and debris from entering the hydraulic system.
9. Label and disconnect the extend/retract hydraulic
hoses at the extend/retract cylinder.
Note: Tag or identify each hose to the corresponding
fitting it was removed from.
10. Remove the lock bolt and pin (1) from the rod end of
the compensating cylinder on the first boom section.
Rest the cylinder on the machine frame.
11. Lower the boom to a level position and place a
suitable support under the rear of the boom.
Reposition the slings to each end of the boom.
12. Remove the lock bolt and pivot pin (2) from rear of
first boom section.
13. Lift the complete boom off machine and set on level
ground or supports being careful not to damage the
tubes on the bottom of the boom.
3.3.2 Second Section Boom Removal
1. Set the complete boom on level ground and by
repositioning the slings, turn boom over on to the top
side. Set the complete boom on suitable stands to
begin tear down.
Note: With the complete boom setting upside down, the
second boom section, tilt cylinder and hoses are made
more accessible. This also eliminates the need to
remove the hose rack on the bottom of the boom.
2. At the boom head, attach a sling through rod end of
tilt cylinder. Remove both hoses from tilt cylinder.
Plug the hose ends and cap the tilt cylinder fittings to
prevent dirt and debris from entering the hydraulic
system. Remove the clip from barrel end of tilt
cylinder pin. Remove the tilt cylinder pin and lift the
tilt cylinder out of the boomhead.
3. At the access panel on the bottom front of the boom,
unscrew the tilt and auxiliary hoses. Plug the hose
ends to prevent dirt and debris from entering the
hydraulic system.
Note: Tag or identify each hose to the corresponding
fitting it was removed from.
4. Carefully pull the tilt, auxiliary and extend/retract
hydraulic hoses (3) through the rear of the second
boom section.
5. Remove the two snap rings and pin from barrel end
of the extend/retract cylinder.
MAH0140
1
2
MAH0660
3