Heater Core
Description
The heater core is located in the HVAC housing. The heater core is a heat exchanger made of rows of tubes with
fins and is positioned within the air distribution housing so that only the selected amount of air entering the housing
passes through the heater core before it is distributed through the heating-A/C system ducts and outlets. One end of
the heater core is fitted with a tank that includes the fittings for the heater core tubes. The heater core can only be
serviced by removing the HVAC housing from the vehicle.
Operation
Engine coolant is circulated through the heater hoses to the heater core at all times. As the coolant flows through the
heater core, heat is removed from the engine and is transferred to the heater core tubes and fins. Air directed
through the heater core picks up the heat from the heater core fins. The blend-air door allows control of the heater
output air temperature by regulating the amount of air flowing through the heater core. The blower motor speed con-
trols the volume of air flowing through the HVAC housing.
Removal & Installation
1. Drain the cooling system (See Cooling System Draining Procedure in Section 06 Cooling System).
2. Evacuate the A/C system (See A/C System Evacuation and Recharge in Section 13 Heating & Air Conditioning).
3. Remove the HVAC housing assembly and place it on a workbench (See HVAC Housing Removal & Installation
in Section 13 Heating & Air Conditioning).
4. Remove the retaining bolts and clamps.
5. Remove the heater core.
6. Installation is in the reverse order of removal.
Installation Notes:
• Verify the cooling system is filled to proper specifications.
ON-VEHICLE SERVICE
13