Peterbilt Medium Duty Truck Owner's Manual - Peterbilt Motors

Preventive Maintenance
WARNING! Do not use any replacement part in
the brake system unless it conforms exactly to
original specifications. A nonconforming part in
your vehicle's brake system could cause a malfunction
resulting in an accident causing death
or injury. Consult you local dealer for suitable
replacement parts.
WARNING! Do not work on the brake system
without the parking brake set, the keys removed
from the vehicle, and wheels chocked securely.
If the vehicle is not properly secured to prevent
inadvertent vehicle movement, it could roll and
cause death, serious personal injury or damage
to the vehicle.
• Use wood blocks (4 in. X 4 in. X 6 in. or
larger) against the front and rear surfaces of
the tires. Be sure the vehicle cannot move.
Brake Fluid Check and Refill
Brake System
WARNING! Wear protective clothing when handling
hydraulic fluid. It is mildly toxic and can
cause skin and eye irritation.
WARNING! Use only the type of hydraulic fluid
specified. Do not use or mix different types of
hydraulic fluid. The wrong hydraulic fluid will
damage the rubber parts of the brake system
which may lead to loss of braking and possibly
cause an accident resulting in death or serious
personal injury.
CAUTION: Hydraulic brake systems use two distinct
and incompatible fluids. Power steering
fluid is used in the hydraulic brake booster system.
Brake fluid is used in the master cylinder
and brake pipes. Do not mix these fluids when
replenishing the system or seal damage can
result.
CAUTION: Hydraulic brake fluid may damage
painted surfaces of the vehicle.
Medium Duty (R05/09) Y53-6027 – 189 –