JLG 723A Service Manual - Manual (Page 34)

Boom
3-4 L2906H, 2906H, 3507H, 619A, 723A, 29.6LP, 29.6, 35.7
10. Remove the lock bolt (3) and pin (4) 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 bolts (5), keeper plate (6) and pivot
pin (7) 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.
3.4.2 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.
2. Remove the access cover from the boom head.
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.
3. At the boom head, attach a sling through rod end of
tilt cylinder. Label and disconnect both hoses (8)
from tilt cylinder. Plug and cap the hose ends to
prevent dirt and debris from entering the hydraulic
system.
4. Remove the lock bolt (9) and pin (10) from the barrel
end of tilt cylinder. Lift the tilt cylinder out of the
boomhead.
5. From the access opening on the bottom front of the
boom, label and disconnect both auxiliary hoses
(11). Plug the hose ends to prevent dirt and debris
from entering the hydraulic system.
6. Carefully pull the tilt, auxiliary and extend/retract
hydraulic hoses (12) through the rear of the second
boom section.
7. Remove the two snap rings and pin (13) from barrel
end of the extend/retract cylinder.
8. Pull the second boom section out 15 cm to 20 cm
(6 in to 8 in) to be able to loosen and remove all the
bolts and remove all the wear pads, backing plates
and shims from the front inside of the first section
boom. Tag each pad, backing plate, shim and bolts
from each location.
9. Remove the clip and pin from the rod end of the
extend/retract cylinder and pull through the rear of
the second boom section.
10. Pull out the remainder of the second boom section.
11. Inspect the boom and welds. Consult your local JLG
distributor if structural damage is detected.
12. Inspect hoses, hardware, wear pads, mounting
points and other components visible with the first
boom section. Replace any item if damaged.
13. Inspect all wear pads for wear. (Refer to Section
3.5.1, “Wear Pad Inspection.”)
MZ5630
5
6 7
5
MZ3650
10
8
9
11
WARNING
NEVER weld or drill the boom. The structural integrity
of the boom will be impaired if subjected to any repair
involving welding or drilling.
MZ3660
13
12
12