Overheated Brakes
PART 7: STARTING & OPERATING THE VEHICLE
Peterbilt tractors without anti-lock brake systems (ABS) are
typically equipped with a bobtail brake proportioning sys-
tem. When a trailer is not connected, the drive axle brake
application pressure will automatically be limited by the pro-
portioning system. When driven in a bobtail mode, these
tractors will require greater brake pedal application to pro-
vide the equivalent braking to a bobtail tractor not equipped
with a proportioning system.
WARNING! Because of the increased use of the
steer axle brakes when driving bobtail, always
ensure the steer axle brakes are functioning
and properly adjusted. Failure to do so can
lead to decreased braking ability, longer stop-
ping distances, loss of vehicle control, and can
cause an accident.
Brake Safety and Emergency
To stop your vehicle in an emergency, vary the service
brake application pressure to provide maximum braking
force without locking the wheels. Use engine compression
to assist the service brakes; i.e., don’t depress the clutch
pedal until the engine reaches idle speed.
WARNING!
• Do not operate the vehicle in the event of a
malfunction in any air circuit. The vehicle
should not be operated until the system is
repaired and both braking circuits, including
all pneumatic and mechanical components,
are working properly. Loss of system air
can cause the service brakes not to function
resulting in the sudden application of the
spring brakes causing wheel lock-up, loss
of control, or overtake by following vehicles.
You could be in an accident and severely
injured.
• Unless you have an anti-lock braking sys-
tem, always avoid completely depressing the
service brake pedal, even during emergency
braking. This action can cause the wheels to
lock, which can lead to an uncontrolled skid
and could cause an accident.
Overheated Brakes
Overheated brakes may be detected by a burning smell
or smoke coming from a brake assembly. If this occurs,
– 92 –
Y53-6015
R(08/07)
Summary of Contents for Peterbilt 320
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Page 210: ...PART 11 SUBJECT INDEX Windshield Washer Reservoir 29 206 Y53 6015 R 08 07 ...
Page 212: ...Peterbilt Motors Company P O Box 90208 Denton Texas 76202 ...