KEY TO CONTROL PANEL (Continued)
PARK BRAKE CONTROL
Never use the parking brake for normal braking.
Pull out to apply parking brakes; push in to release
N O T E
The Park Brake Indicator will come on when
t h e c o n t r o l i s i n t h e a p p l i e d p o s i t i o n .
TRAILER AIR SUPPLY CONTROL
Supplies air to trailer air reservoirs. Push in to supply
air to (charge) trailer reservoirs after releasing PARK
BRAKE. Pull out to shut off air to trailer. When
P A R K B R A K E C o n t r o l i s a p p l i e d ( p u l l e d o u t ) ,
T R A I L E R A I R S U P P L Y C O N T R O L w i l l a u t o -
If tractor air system pressure drops to 60 PSI,
the trailer air supply protection valve will trip,
fully applying trailer spring brakes. Brakes will
not release until more than 60 psi is reached.
ENGINE RETARDER SELECTION SWITCH
Selects the number of engine cylinders desired for
the braking action. HIGH position provides maxi-
mum engine braking (6 cylinders), MED position
provides braking on 4 cylinders, and LOW position
provides braking on 2 cylinders.