JLG 4017PS Service Manual - Manual (Page 58)

Boom
3-20 3706PS, 3707PS, 4014PS, 4017PS, 33.7, 37.6, 37.7
3.8.4 Tilt/Auxiliary Hose Installation
1. Fasten the rope/wire left in the boom from the hose
removal to each end of the new hose at the rear of
boom.
2. Slowly pull the rope/wire from the boom head until
the hose end is visible at the boom head.
3. Slowly pull the rope/wire from below the first boom
section until the hose end is visible at the tube
connections.
4. Unfasten the rope/wire from each end of the hose.
5. Uncap and connect the hoses to the previously
labeled tubes under the first boom section. Refer to
Section 2.3.3, “Hydraulic Hose Torque Chart,” for
proper hose torque.
6. Uncap and connect the hoses to the previously
labeled fittings at the tilt cylinder or the auxiliary
fittings. Refer to Section 2.3.3, “Hydraulic Hose
Torque Chart,” for proper hose torque.
7. Install and tighten the clamps holding the tilt hoses
at the rear of the third boom section.
8. Properly connect the battery.
3.9 EXTEND/RETRACT CYLINDER
REMOVAL/INSTALLATION
The extend/retract cylinder hydraulically extends and
retracts the third boom section.
Seal kits for the extend/retract cylinders are available
from the local JLG dealer.
3.9.1 Extend/Retract Cylinder Removal
1. Remove any attachment from the quick coupler
assembly. Refer to Operation & Safety Manual.
2. Park the machine on a hard, level surface, extend
the boom to gain access to the extend/retract
cylinder pin in the third boom section, level the boom
assembly, 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. Remove the cylinder rod eye mounting pin (1) at the
side of the third boom section.
5. Start the machine and SLOWLY retract the extend/
retract cylinder and at the same time manually
retract the third boom section.
6. Shut the engine OFF.
7. Open the engine cover. Allow the system fluids to
cool.
8. Properly disconnect the battery.
9. Loosen and remove the extend/retract cylinder
hoses at the rear of the boom assembly. Plug the
hose ends to prevent dirt and debris from entering
the hydraulic system.
10. Remove the cylinder barrel end pin (2). Note the
location of the spacers and washers
11. 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.
12. Place the extend/retract cylinder in a designated
area for the next operation.
3.9.2 Extend/Retract Cylinder Installation
1. 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 second boom section. Be
certain that the wear pads are installed on the
cylinder.
MAM0980
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