SkyTrak 8042 Service Manual - Manual (Page 65)

Boom
3.4 Model 8042, 10042, 10054 Legacy Rev. 03/04
3.2 BOOM SYSTEM - THREE SECTION
BOOMS (8042 AND 10042)
3.2.1 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.
3.2.2 Boom System Operation
The three section boom assembly consists of inner,
intermediate, and outer boom assemblies with double top
boom extend chains and a single retract chain. Boom
extension and retraction is accomplished via hydraulic
power and chain movement.
As the Extend/Retract hydraulic cylinder, which is
anchored at the rear of the intermediate boom and the
rear of the outer boom, begins to extend, it forces the
intermediate boom out of the outer boom.
The inner and outer booms are connected by extend and
retract chains. These chains are routed around sheaves
on the intermediate boom. As the intermediate boom is
forced out, the extend chain pulls the inner boom out of
the intermediate boom.
As hydraulic pressure is applied to the retract port on the
Extend/Retract cylinder, the intermediate boom is pulled
back into the outer boom, and the retract chain pulls the
inner boom back into intermediate boom.
This mechanical linkage formed by the chains and
supporting hardware extends and retracts the intermediate
and inner booms at the same rate.
The outer boom does not extend or retract, but lifts and
lowers via action of the Lift/Lower cylinder.
3.3 BOOM ASSEMBLY MAINTENANCE
(8042 AND 10042)
The boom assembly consists of the inner, 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, intermediate and outer boom removal
instructions must be completed in sequence. The inner
boom must be removed before removing the intermediate
boom. The inner boom and intermediate boom must be
removed one at a time before removing the outer boom.
Before beginning, conduct a visual inspection of the
vehicle, work area and 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 8042 Legacy
Owners/Operators Manual or Model 10042 Legacy
Owners/Operators Manual.)
2. Check chain wear and tension adjustment. (Refer to
Section 3.4.1, “Boom Chain Inspection,” and Section
3.4.3, “Boom Chain Tension Check.”)
3. Apply grease at all lubrication points (grease fittings).
(Refer to Model 8042 Legacy Owners/Operators
Manual or Model 10042 Legacy Owners/Operators
Manual.)
4. Check for proper operation by operating all boom
functions through their full range of motion several
times.
WARNING:
DO NOT service the vehicle
without following all safety precautions as
outlined in the “Safety Practices” section of this
manual. Failure to follow the safety practices
may result in death or serious injury.