SkyTrak 8042 Service Manual - Manual (Page 125)

Boom
3.64 Model 8042, 10042, 10054 Legacy Rev. 03/04
3.5 BOOM SYSTEM - FOUR SECTION
BOOM (10054)
3.5.1 Boom System Description
The boom operates via an interchange among the
electrical, hydraulic and mechanical systems. Components
involved include the joystick, Attachment Tilt cylinder,
Extend/Retract cylinder, Lift/Lower cylinder, Slave
cylinders, electronic sensors, extend and retract chains,
various pivots, supporting hardware and other components.
3.5.2 Boom System Operation
The four section boom consists of the inner, secondary
intermediate, primary intermediate and outer boom
assemblies with double intermediate boom extend
chains, a single inner boom extend chain, a single inner
boom retract chain and a single intermediate boom
retract chain.
As the Extend/Retract hydraulic cylinder, which is
anchored at the front of the primary intermediate boom,
and the rear of the outer boom begins to extend, it forces
the primary intermediate boom out of the outer boom.
The inner, secondary intermediate, primary intermediate
and outer booms are connected by extend and retract
chains. These chains are routed around sheaves on the
secondary and primary intermediate booms. As the
primary and secondary intermediate booms are forced
out, the extend chain pulls the inner boom out of the
secondary intermediate boom.
As hydraulic pressure is applied to the retract port on the
Extend/Retract cylinder, the secondary intermediate
boom is pulled back into the outer boom, and the retract
chain pulls the secondary intermediate and inner booms
back into the primary intermediate boom.
This mechanical linkage formed by the chains and
supporting hardware, extends and retracts the primary
and secondary intermediate booms and inner boom at
the same rate.
The outer boom does not extend or retract, but lifts and
lowers via action of the Lift/Lower cylinders.
3.6 BOOM ASSEMBLY MAINTENANCE
(10054)
The boom assembly consists of the inner, secondary and
primary intermediate, and outer booms and supporting
hardware.
IMPORTANT: Boom replacement must be completed in
sequence, one boom section at a time, as described in
these instructions. Replacement of two or more boom
sections as a unit requires special considerations that
are not covered in these instructions.
IMPORTANT: Before removing the inner boom, the
carriage or any other attachment must be removed from
the quick attach.
The inner, secondary and primary intermediate, and
outer boom removal instructions must be completed in
sequence. The inner boom must be removed before
removing the secondary and primary intermediate
booms. The inner boom, and secondary and primary
intermediate booms must be removed one at a time
before removing the outer boom.
Before beginning, conduct a visual inspection of the
vehicle and work area, and review the task about to be
undertaken. Read, understand and follow these
instructions.
After servicing the boom, perform the following:
1. Check wear pads. (Refer to Model 10054 Legacy
Owners/Operators Manual.)
2. Check chain wear and tension adjustment. (Refer to
Section 3.7.1, “Boom Chain Inspection,” and Section
3.7.3, “Boom Chain Tension Check.”)
3. Apply grease at all lubrication points (grease fittings).
(Refer to Model 10054 Legacy Owners/Operators
Manual.)
4. Check for proper operation by operating all boom
functions through their full ranges of motion several
times.