JLG 723A Service Manual - Manual (Page 37)

3-7 L2906H, 2906H, 3507H, 619A, 723A, 29.6LP, 29.6, 35.7
Boom
7. Loosen and remove the cover plate from the rear of
the frame assembly.
8. Label and disconnect the tilt and auxiliary hydraulic
hoses (7) attached to the tubes at the bottom rear of
the boom. Plug and cap the hose and tube ends to
prevent dirt and debris from entering the hydraulic
system.
9. Label and disconnect the extend/retract cylinder
hoses at the rear of the extend/retract cylinder (8).
Plug the hose ends to prevent dirt and debris from
entering the hydraulic system.
10. Loosen and remove both fittings from the bottom of
the extend/retract cylinder barrel. Plug the openings
in the extend/retract cylinder barrel.
11. Remove the snap ring on each side of the extend/
retract cylinder mounting pin.
12. Remove the mounting pin (9).
13. Attach a sling or other suitable lifting device to the
extend/retract cylinder and carefully pull the extend/
retract cylinder free of the machine through the rear
of the boom/chassis assembly.
14. Place the extend/retract cylinder in a designated
area for the next operation.
3.4.6 Extend/Retract Cylinder Installation
1. Using a suitable sling, carefully install the extend/
retract cylinder into the rear of the boom and line up
the barrel end of the cylinder with the pin bores on
the first boom section.
2. Install the mounting pin (9) through the frame access
hole on the chassis and the first boom section bore
and cylinder barrel. Secure with snap rings.
3. Remove the plugs in the bottom of the extend/retract
cylinder and install the previously removed fittings.
4. Uncap and connect the hoses to the previously
labeled fittings at the extend/retract cylinder (8).
Apply Loctite
® 545 TM to the fittings.
5. Uncap and reconnect the tilt hoses and auxiliary
hoses (7) to their appropriate fittings until wrench-
tight. Mark the fitting and torque to specification.
Refer to Section 2.2.3, “Hydraulic Hose Torque
Chart.”
6. Install the cover plate at the rear of the boom
assembly.
7. Properly connect the battery.
8. Start the machine and extend the extend/retract
cylinder until the rod eye of the cylinder aligns with
the pin bore in the second boom section.
9. Shut the engine OFF.
10. Install the mounting pin through the side of the
second boom section (6) and secure with the snap
rings.
11. Start the machine and cycle the extend/retract
cylinder to bleed any air out of the hydraulic system.
Check for oil leaks or any alignment problems.
Check the hydraulic oil level in the tank and add oil
as required.
12. Close and secure the engine cover.
13. Remove the Do Not Operate Tags from both the
ignition key switch and the steering wheel.
MZ3690
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8
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