Boom Retraction; Maintenance; Removal; Boom Extension - Manitowoc Grove RT765E-2 Service And Maintenance Manual

BOOM
allowing the lower cylinder to extend. When the lower
cylinder is fully extended, the check valve for the upper
cylinder opens allowing the upper cylinder to extend. The
check valve for the lower cylinder closes after the upper
cylinder starts to extend and shuts off the flow to the lower
cylinder. As the upper telescope cylinder barrel extends, the
extend cables around the extend sheaves on the end of the
cylinder barrel push on the extend cables to pull the fly
section out at the same time the outer mid is extending.

Boom Retraction

The upper telescope cylinder retracts the outer-mid and two
retract cables pull the fly section in at the same time. When
the upper cylinder is fully retracted, the check valve for the
lower telescope cylinder is opened and the lower cylinder
starts to retract. The check valve for the upper cylinder is
closed as the lower cylinder starts to retract.

MAINTENANCE

Removal

NOTE: The boom assembly must be rotated 180° (upside
d o w n ) b e f o r e p e r f o r m i n g a n y a s s e m b l y o r
disassembly procedures.
4-2
.
A rollover fixture with webbing is recommended to rotate
boom and sections. Chains are not recommended. If a
rollover fixture is not available, rotate sections using
adequate support with webbing.
A secure fixture that will prevent damage to the boom is
recommended to stabilize and hold the boom from moving
during removal of any section or sections.
NOTE:
NOTE:
Published 9-04-2014, Control # 422-08
RT765E-2 SERVICE MANUAL
CAUTION
The boom may be disassembled with the base
section left on the crane if repair of the base section
is not necessary.
The boom weighs approximately 18,179 lb (8246
kg). Removal of the swingaway boom extension
will simplify boom removal, therefore, the above
weight is for the boom without the swingaway
boom extension attached.