Preventive Maintenance Brake System
Medium Duty
(R10/06) Y53-6008 – 149 –
BRAKE SYSTEM
If your truck has an air brake system, see the pages below.
If your truck has a hydraulic brake system, please go to
“
Hydraulic Brake System” on page 153.
Introduction
To operate your vehicle safely, you need some understanding
of its brake systems. Brake adjustment and brake balance
must be set carefully to allow equal stopping forces at all
wheels. Tires are also a very important part of the whole sys-
tem. How fast you can stop depends on how much friction
there is between the road and your tires.
CAUTION: The air brake system of this vehicle
was configured for ONE of the following opera-
tions: tractor or truck, and complies with the
respective portions of FMVSS 121. A tractor
shall not be operated or configured as a truck,
nor shall a truck be operated or configured as a
tractor, without significant modifications to the
air brake system in order to retain compliance
with FMVSS 121. Contact your Peterbilt dealer
for instructions.
All of the following areas are interrelated and must con-
form to original specifications:
Once a brake system is set to specifications, changing any
one of its components or any combination of components
may degrade the system. All parts have to work together to
perform as they should.
Because your brake system is air operated, see the following
section “
Air System” on page 160 for more information on
checking your brakes.
Any replacement components in the brake system should be
the same or better than the original components. Any
changes from the original specifications can affect the perfor-
mance of the entire system.
• tire size • cam radius
• wedge angle • drum radius
• brake linings • brake chambers
• slack adjusters
