JLG 4017PS Service Manual - Manual (Page 44)

Boom
3-6 3706PS, 3707PS, 4014PS, 4017PS, 33.7, 37.6, 37.7
3.3.3 Second Section Boom Removal
1. Remove any attachment from the quick coupler
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 a Do Not Operate Tag on both the ignition key
switch and the steering wheel.
4. Properly disconnect the battery.
5. Open the engine cover. Allow the system fluids to
cool.
6. Remove the quick coupler assembly. Refer to
Section 3.18.1, “Quick Coupler Removal (3706PS,
3707PS, 33.7, 37.6 & 37.7).”
7. Label, disconnect and cap the tilt hoses and (if
equipped) auxiliary hydraulic hoses attached to the
machine at the boom head. Plug and cap the hose
ends to prevent dirt and debris from entering the
hydraulic system.
8. Place a sling around the tilt cylinder and remove the
retaining rings and pin at the barrel end of the tilt
cylinder. Remove tilt cylinder.
9. Label, disconnect and cap the extend/retract
hydraulic hoses on the extend/retract cylinder at the
rear of the boom. Plug and cap the hose ends to
prevent dirt and debris from entering the hydraulic
system.
10. Remove the top and side wear pads from the rear of
the second boom section.
Note: Tag each pad, backing plate, shim and bolts from
each location.
11. Remove the retaining rings (1) from the rear of the
extend/retract cylinder.
12. Remove the extend/retract cylinder mounting pin (2).
Note: Tag each spacer and shim from each side of the
extend/retract cylinder.
13. Support the front of the boom by placing a sling
behind the boom head. Pull the second boom
section out of the first boom section approximately
15 cm to 20 cm (6 in to 8 in).
14. Pull the tilt hoses and (if equipped) auxiliary
hydraulic hoses through the rear of the boom.
15. Remove the top, side and bottom wear pads from
the front of the first boom section.
Note: Tag each pad, backing plate, shim and bolts from
each location.
16. Pull the second boom section halfway out of the first
boom section, reposition the sling, balancing the
second boom section and remove from the first
boom section.
17. Set the second boom section on level ground. Set
the complete boom on suitable stands to begin tear
down.
18. Inspect the boom and welds. Consult the local JLG
dealer if structural damage is detected.
19. Inspect hoses, hardware, wear pads, mounting
points and other components visible with the first
boom section. Replace any item if damaged.
20. Inspect all wear pads for wear. (Refer to Section
3.17.1, “Wear Pad Inspection.”)
3.3.4 First Boom Section Removal
1. Temporarily connect the battery.
2. Remove boom angle sensor arm. Refer to Section
9.12.7, “Boom Angle Sensor.”
3. Start the machine and raise the first boom section to
gain access to the lift cylinder pin and the
compensation cylinder pin.
4. Properly disconnect the battery.
5. Support the first boom section by placing a sling at
the balance point of the section.
MAM0620
2
1
1
WARNING
DO NOT activate ANY boom function other than the
boom lift/lower function. Activating the extend/retract,
tilt or auxiliary function could cause hydraulic oil to
spray onto the machine and/or surrounding areas.