JLG 4017RS Service Manual - Manual (Page 45)

3-5 3614RS, 4017RS
Boom
3.3.1 Boom Removal
While the boom sections can be separated from each other
on the machine, it is much safer, more efficient and more cost
effective to remove the complete boom assembly from the
machine and place it on suitable supports for separation.
Work can then progress at a normal working height.
Note: When removing a complete boom assembly use a hoist
or crane with a minimum lift capacity of 2721 kg (6000 lbs).
1. Remove any attachment from the quick coupler. Refer
to Operation & Safety Manual.
2. Remove the quick coupler assembly. Refer to Section
3.17.1, “Quick Coupler Removal.”
3. Park the machine on a hard, level surface, fully retract
the boom, raise the boom assembly to access lift/lower
cylinder pin and the compensation cylinder pin, place
the transmission in (N) NEUTRAL, engage the park brake
and shut the engine OFF.
4. Place a Do Not Operate Tag on both the ignition key
switch and the steering wheel.
5. Open the engine cover. Allow the system fluids to cool.
6. Properly disconnect the battery.
7. Close engine cover to access lift/lower cylinder pin and
the compensation cylinder pin.
8. Properly support the boom assembly using a hoist or
crane.
9. Remove boom angle sensor arm. Refer to Section 9.8.7,
“Boom Angle Sensor.”
10. Remove the pin from the rod end of the lift/lower
cylinder being careful not to drop the cylinder. Lower
the cylinder to a secure position.
11. Remove the pin from the rod end of the compensation
cylinder being careful not to drop the cylinder. Lower
the cylinder to a secure position.
12. Lower the boom assembly to level.
13. Place a sling around the first boom section at the
balance points.
14. Label, disconnect and cap all hydraulic hoses attached
to the tubes on the bottom of the boom. Cap all fittings
and openings to keep dirt and debris from entering the
hydraulic system.
15. Raise the boom assembly to allow the removal of the
boom assembly pivot pins.
16. Confirm that the boom assembly is balanced with the
sling and remove the boom assembly pivot pins.
17. Lift the boom assembly from the machine and lower
onto suitable supports.
3.3.2 Second, Third Boom Section Removal
1. Verify the boom assembly is setting on stable, secure
and suitable supports.
2. Properly support the extend/retract cylinder (1) using a
hoist or crane.
3. Label, disconnect and cap the extend/retract cylinder
hoses (2) from the extend/retract cylinder. Cap all
fittings and openings to prevent dirt and debris from
entering the hydraulic system.
4. Loosen and remove the extend/retract cylinder bracket
(3).
5. Remove one retaining ring from the mounting pin (4) at
each end of the extend/retract cylinder.
6. Remove each mounting pin and remove the extend/
retract cylinder and place in a secure location.
7. Label, disconnect and cap the tilt circuit hoses from the
tilt cylinder at the front of the third boom section. Label,
disconnect and cap the auxiliary circuit hoses from the
quick disconnect fittings at the front of the third boom
section. Cap all fittings and openings to prevent dirt and
debris from entering the hydraulic system.
8. Place a sling through the opening at the top of the
boom head and around the tilt cylinder and remove the
retaining rings and pin at the barrel end of the tilt
cylinder. Lower the tilt cylinder and place in a secure
location.
9. Loosen and remove the rear cover and door assembly
from the rear of the first boom section.
MZ7090
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