JLG 740AJ, Service And Maintenance Manual

Page: 405 / 582

SECTION 5 - BASIC HYDRAULIC INFOR M ATION AND SCHE M ATICS
3121160 5-61
7. Using auxiliary power from ground controls, retract the
lift cylinder rod completely.
8. Disconnect, cap, and tag the main boom lift cylinder
hydraulic lines and ports.
9. Remove mounting hardware securing the telescope cyl-
inder barrel to the main base boom.
10. Using an external pump, extend the cylinder as far as
the hydraulic lines will allow to enable a lifting device to
be attached to the telescope cylinder.
HYDRAULIC LINES AND PORTS SHOULD BE CAPPED IMMEDIATELY AFTER DIS-
CONNECTING LINES TO AVOID THE ENTRY OF CONTAMINANTS INTO THE SYS-
TEM
11. Tag and disconnect hydraulic lines from telescope cylin-
der. Use suitable container to retain any residual hydrau-
lic fluid. Cap hydraulic lines and ports.
NOTE: The Telescope Cylinder weighs approximately 459 lbs.
(208.2 kg).
12. Secure the telescope cylinder with a suitable sling and
lifting device.
13. Carefully remove the telescope cylinder from the main
boom assembly and place in a suitable work area.
Main Boom Telescope Cylinder Installation
1. Using suitable lifting equipment, carefully insert the cyl-
inder into the boom assembly.
2. Remove the lifting device from the telescope cylinder.
3. Carefully install main telescope cylinder rod pin through
the fly boom and secure it with the retaining rings.
4. Remove applicable hydraulic line and port caps and
properly connect the hydraulic lines to the telescope
cylinder. Ensure all hoses are correctly routed.
5. Carefully install the telescope cylinder barrel end sup-
port into mounting block in base boom and secure with
blocks and torque the bolts to 35 ft. lbs. (48 Nm). Use JLG
Threadlocker P/N 0100011 on bolts. Shim as necessary.