Heater and Air Conditioner Preventive Maintenance
– 180 – Y53-6008
Medium Duty (R10/06)
HEATER AND AIR CONDITIONER
Introduction
The combination heater-air conditioner provides comfort for
those in the cab through accurate control of the cab environ-
ment in all weather conditions. Regular attention to the items
below will help you keep the heater-air conditioner unit run-
ning well.
Special Precautions
WARNING! Excessive heat may cause the pres-
surized components of the air conditioning sys-
tem to explode. Never weld, solder, steam clean,
or use a blow torch near any part of the air con-
ditioning system.
• If a refrigerant leak develops in the presence of
excessive heat or an open flame, hazardous gases
may be generated. These gases may cause uncon-
sciousness or death. If you become aware of a refrig-
erant leak on your vehicle have your system service
immediately and observe the following precautions:
– Stay away from the hot engine until the exhaust
manifold has cooled.
– Do not permit any open flame in the area. Even a
match or a cigarette lighter may generate a haz-
ardous quantity of poisonous gas.
– Do not smoke in the area. Inhaling gaseous
refrigerant through a cigarette may cause violent
illness.
Heater
• Check all heater controls for full-range operation.
• Check hoses, connections, and heater core for condition
and leaks.
• Check the drain pan of the fresh air vent for trapped
water before assuming that there is a leak in the heating
system. If the heater core is leaking, a reliable radiator
shop should be able to repair it.
• Check the heater core for debris blocking the air flow. If
the blower and air controls are functioning properly, yet
the heater is not operating properly, the heater core or
the hot water valves may be clogged or closed. Clean
the heater core if necessary. If the condition persists,
take the vehicle to a Peterbilt Dealer for proper heater
service or repair.
