Main Boom Installation; Boom Maintenance; Disassembly Of The Main Boom - JLG H340AJ Service And Maintenance Manual

Main Boom Installation

NOTE: The main boom alone weighs approximately 472 lbs (214.1
kg).
1. Using all applicable safety precautions, carefully lift
main boom assembly to align the pivot holes in the
main boom with those of the upper upright.
2. Using all applicable safety precautions, carefully lift and
align main boom assembly with the upper upright.
Using a soft head mallet, install pivot pin into upper
upright and secure with bolt and pin keeper.
3. Using all applicable safety precautions, carefully lift and
align master cylinder with the upper upright. Using a
soft head mallet, install cylinder pin into upper upright
and secure with bolt and pin keeper.
4. Using all applicable safety precautions, carefully align
master cylinder with the main boom. Using a soft head
mallet, install cylinder pin into main boom and secure
with bolt and pin keeper.
5. Using all applicable safety precautions, carefully lift and
align upper lift cylinder with the upper upright. Using a
soft head mallet, install cylinder pin into upper upright
and secure with bolt and pin keeper.
6. Using all applicable safety precautions, carefully align
upper lift cylinder with the main boom. Using a soft
head mallet, install cylinder pin into main boom and
secure with bolt and pin keeper.
7. Connect hydraulic lines to the master cylinder and
upper lift cylinder as tagged during removal.
8. Install the jib and platform assembly. Refer to Section 4.5
- Jib.
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SECTION 4 - BOOM & PLATFORM

4.4 BOOM MAINTENANCE

Disassembly of the Main Boom

1. Loosen the wear pad retaining bolts at the rear of fly
boom section and remove the shims and wear pads not-
ing the location and amount of shims to aid in reassem-
bly.
2. Using a portable power source, attach hose to telescope
cylinder port block. Using all applicable safety precau-
tions, activate hydraulic system and extend cylinder to
gain access to cylinder rod retaining pin. Shut down the
portable power source.
3. Carefully disconnect hydraulic hose from retract port of
cylinder. There will be initial weeping of hydraulic fluid
which can be caught in a suitable container. After initial
discharge, there should be no further leakage from the
retract port. Cap or plug all openings.
NOTE: When removing the retaining pin from the rod end of the
telescope cylinder, make sure the cylinder is properly sup-
ported.
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