User Manual

WARNING
DO NOT leave the cab of your vehicle
without
applying the parking brake.
The truck could roll and cause an acci-
dent resulting in death or personal in-
jury. Always apply the parking brake
before you leave the cab.
Combination (Vehicle/Trailer) Parking Brake Control
V
alves
1. Parking Brake Control (Yellow)
2.
Trailer Air Supply Control (Red)
Before You Leave the Cab
1. Apply all parking brakes. Pull out
the Yellow Parking Brake Control
knob (1) located on the dash. The
Red (octagon-shaped) Trailer Air
Supply Control knob will
automatically pop out. (A dash
warning light will indicate when the
brake is ON.)
2.
Shift the transmission into PARK
position:
• manual transmission, select
First or Reverse gear.
• automatic transmission, select
Neutral.
3. Turn the key to OFF.
4. Remove the key.
WARNING
Do not pull out the parking brake valve
while
the vehicle is moving. Stopping
with the parking brake controls can
cause a sudden wheel lockup, loss of
control, or over-take by following vehi-
cles. Failure to comply may result in
property damage personal injury, or
death.
The parking brakes act on the rear wheels
only. They are spring-applied, with air
pressure used to release them. Release air
is supplied by both the front and rear circuit
air tanks through a double check valve.
To Release the Vehicle Parking
Brakes ONL
Y
• Push IN the Yellow knob on the
dash. Your trailer will remain
parked.
• Below 60 psi (414 kPa) the Yellow
parking brake valve remains OUT
(ON position). If air pressure is not
restored above 60 psi (414 kPa),
the knob will automatically return to
the OUT position if you attempt to
push it in. Check the Primary and
Secondary Air Pressures in the
Primary Gauges gauge view.
To Release the Trailer Brakes ONLY
• Push IN the Red knob on the dash.
The vehicle will remain parked.
To Release the Full Combination of
Brakes
• Push IN BOTH knobs on the dash.
• In the event that air pressure is
reduced below a safe level: the low
air warning light will come on first; if
air pressure continues to drop, the
parking brake valve will pop OUT,
automatically applying the spring
brakes.
DRIVING - Air Brake System (option)
Y53-6113-1A1 (11/20) 137
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