SKYJACK, Page 23
Section 2 - Operation
August 2007
SJM & SJII Series
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2-16. Free-Wheeling Valve
Free-Wheeling Valve - The free-wheeling valve is lo-
cated at the front and/or rear of the machine.
(depending on model)
Figure 2-11a. Free-Wheeling Valve (SJM Series)
Figure 2-11b. Free-Wheeling Valve (SJll Series)
1. Free-Wheeling Valve - Turning the valve knob
(counterclockwise) to a fully opened position
allows fluid to flow through the wheel motors, thus
providing “free-wheeling” so that the aerial platform
can be pushed, towed or winched after the brakes
are released without damaging the wheel motors.
The Free-wheeling valve MUST be closed tightly
(clockwise) for normal operation.
Note
Refer to “section 2-26” For Winching and Towing
procedure.
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2-14. Powered Extension Deck Control Box (If
Equipped)
This metal control box is mounted on the extension
platform guard rail. It contains the following controls:
Figure 2-9. Powered Extension
Deck Control Box
1. Enable Switch - This switch, when activated
and held allows the Extension Deck Extend/
Retract Switch functions to operate.
2. Extend/Retract Switch - This switch, when
activated, extends or retracts the powered
extension deck.
2-15. Parking Brake
Parking Brake - The parking brakes are devices that are
always mechanically engaged until hydraulically or
manually released.
Figure 2-10. Parking Brake
A pin retracted by a single-acting hydraulic cylinder
disengages each brake disc when driving. Remove the
Cotter Pin and Stabilizer Lock Pin and fully extend each
stabilizer. A spring inside each cylinder returns the pin
to engage the brake disc for parking, lifting, lowering
and stationary steering. The brake pin MUST be manu-
ally disengaged for towing, pushing or winching.
Note
Refer to “section 2-26” For Winching and Towing
procedure.