Service Manual

SECTION 5 - HYDRAULICS
3121202 – JLG Lift – 5-3
7. Using a suitable brass drift, carefully drive the push
bar pins from the telescope cylinder rod and turnta-
ble.
8. Remove hardware securing cable adjustment block
to aft end of the base boom section and remove
block.
9. Remove hardware securing telescope cylinder to aft
end of the mid boom section.
WHEN REMOVING THE TELESCOPE CYLINDER FROM THE BOOM,
IT MAY BE NECESSARY AT SOME POINT TO TURN THE CYLINDER
SLIGHTLY IN ORDER TO CLEAR ASSEMBLIES MOUNTED WITHIN
THE BOOM. CARE MUST BE TAKEN TO MOVE THE CYLINDER
SLOWLY INTO POSITION: DAMAGE TO COMPONENTS MAY
RESULT FROM FORCIBLE IMPACT WITH THESE ASSEMBLIES.
10. Remove bolts securing cable attach bar to top of fly
boom section.
11. Pull the telescope cylinder and cables partially from
aft end of the base boom section; secure the cylin-
der with a suitable sling and lifting device at approxi-
mately the center of gravity.
12. Carefully remove the telescope cylinder and sheave
assembly. Place telescope cylinder on a suitable
trestle.
Main Boom Telescope Cylinder Installation
1. Route extend cables around extend sheave and
secure cables to the telescope cylinder.
2. Install extend cables mounting blocks to threaded
ends of cables. Loosely install nuts and jam nuts
onto the threaded end of cables.
NOTE: When installing cables care must be taken not to
twist or cross the cables.
3. Secure the sling and lifting device at the telescope
cylinder’s approximate center of gravity, and lift the
cylinder to the aft end of the boom assembly.
4. Install extend cable mounting blocks to threaded
ends of cables. Loosely install nuts and jam nuts
onto the threaded ends of cables.
NOTE: When installing cables, care must be taken not to
twist or cross the cables.
5. Secure the sling and lifting device at the telescope
cylinder’s approximate center of gravity, and lift the
cylinder to the aft end of the boom assembly.
WHEN INSERTING THE TELESCOPE CYLINDER INTO THE BOOM,
IT MAY BE NECESSARY AT SOME POINT TO TURN THE CYLINDER
SLIGHTLY IN ORDER TO CLEAR ASSEMBLIES MOUNTED WITHIN
THE BOOM. CARE MUST BE TAKEN TO MOVE THE CYLINDER
SLOWLY INTO POSITION: DAMAGE TO COMPONENTS MAY
RESULT FROM FORCIBLE IMPACT WITH THESE ASSEMBLIES.
6. Carefully install the telescope cylinder barrel end
support into slots in mid boom and secure with
blocks and bolts. Use Loctite #242 on bolts.
7. Align holes in aft end of the fly boom section with
holes in cable mounting block, then secure with
mounting hardware.
8. Align holes in aft end of the base boom section with
holes in cable mounting block, then secure with
mounting hardware.
9. Remove cylinder port plugs and hydraulic line caps
and correctly attach lines to cylinder ports.
Figure 5-1. Boom Positioning and Support, Cylinder Repair