Regional Haul Model Operator's Manual - Peterbilt Motors Company

STARTING AND OPERATING THE VEHICLE
WARNING! The service brakes must be used
in an emergency. The engine or retarder alone
might not stop you fast enough to prevent an
accident. You could be killed or injured if you
relied only on the engine retarder.
• The engine retarder is NOT intended as the
primary brake for the vehicle, nor is it an
emergency brake. The engine retarder only
helps the service brakes by using pressure
to slow the drivetrain. Use the service
brakes for quick stops.
Exhaust Brake
With the exhaust brake switch ON, the brake automatically
creates its braking effect when you remove your foot
from the accelerator pedal.
The brake switch is located on the accessory dash panel.
It controls whether the brake is ON (ready to slow the
vehicle down) or OFF (no braking action).
• Do not use the engine retarder (such as an exhaust
brake) to slow the vehicle down when you are bobtailing
or pulling an empty trailer.
ENGINE RETARDER (OPTION)
• Make sure the brake is OFF before starting the
engine.
• After the engine is started, warmed up, and you are
ready to get under way, turn the exhaust brake switch
ON for added braking effect.
WARNING! Do not use the engine retarder
when operating on road surfaces with poor
traction (such as wet, icy, or snow covered
roads or gravel). Retarders can cause the
wheels to skid on a slippery surface. You
could lose control of the vehicle and/or jackknife
if the wheels begin to skid, resulting in
an accident, causing death or personal injury.
However, if your vehicle is equipped with Rockwell/
WABCO anti-lock brakes (ABS), the operation of the
exhaust brake (if turned ON) will be controlled by the ABS.
For more ABS information, see “Anti-Lock Braking System”
on page 110.
For more information on when and how to use the engine
retarder in your vehicle, see the owner’s manual for the
engine brake that is included with your vehicle.
Regional Haul (R05/10) Y53-6033 – 115 –