INSTRUMENT PANEL (Con't).
Upper Right Dash Panel.
Control or Indicator
Vent air into cab from heater/ventilator/defroster and air
conditioner. Louvered openings are adjustable.
Engine (Jake) Brake
Selects number of engine cylinders desired for braking
action (two, four, or six cylinders). Turn on left switch for
two cylinders, right switch for four cylinders, and both
switches for all six cylinders.
Fifth Wheel Slide
Permits repositioning of sliding fifth wheel from inside
cab. LOCK position deactivates control valve and locks
fifth wheel to baseplate. UNLOCK position activates
control valve to allow changes to total length of tractor-
trailer and changes to axle loads.