SkyTrak 6042 Service Manual - Manual (Page 49)

3.3 Model 6042 Legacy Origin 7/02
Boom
3.2 BOOM SYSTEM
3.2.1 Boom System Description
The boom operates via an interchange among the
hydraulic and mechanical systems. Components
involved include the joystick, attachment tilt cylinder,
extend/retract cylinder, lift/lower cylinders, slave
cylinders, extend and retract chains, various pivots,
supporting hardware and other components.
3.2.2 Boom System Operation
The 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 front 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 the 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 cylinders.
3.3 BOOM ASSEMBLY MAINTENANCE
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.
Note: A step ladder or some other safe means of
accessing the boom will be necessary.
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 for excessive wear. (Refer to
appropriate 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 appropriate 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.