Peterbilt Medium Duty Trucks Operator's Manual after 1-07

Preventive Maintenance
8. Idle the engine until it reaches normal operating temperature.
9. Fill the radiator as necessary to raise the coolant level to
the proper reading. Replace the surge tank pressure
cap.
Engine (Block) Heater (option)
WARNING! Do not use the heater if there are any
signs of problems. Engine block heaters can
cause fires resulting in serious personal injury
and/or property damage if not properly maintained
and operated. Regularly inspect the
engine block heater wiring and connector for
damaged or frayed wires. Contact your Authorized
Service Center or the manufacturer of the
heater if you are in need of repairs or information.
Engine Cooling System
CAUTION: Always unplug the block heater
before starting your engine. Damage to the cooling
system could occur if not turned OFF
(unplugged).
Use a solution of half ethylene glycol antifreeze and half
water for best heater performance. Do not use more than 65
percent concentration of antifreeze, as a shortened heater
life will result.
After servicing the cooling system, operate the vehicle for a
day or two before using the heater. Trapped air inside the
engine needs time to escape.
Medium Duty (R10/06) Y53-6008 – 147 –