Heater Core: Service and Repair

Less Air Conditioning
1. Disconnect battery ground cable.
2. Remove instrument panel and, on Mustang models, the floor console. Service and Repair
3. On Cougar and Thunderbird models, remove righthand instrument panel brace from cowl.
4. On all models, drain cooling system, then disconnect hoses from heater core. Plug core and hoses to prevent contamination.
5. Remove air inlet duct and blower housing assembly housing support bracket-to-cowl top panel attaching screw.
6. Disconnect vacuum supply hose from in-line check valve in engine compartment.
7. Disconnect blower motor electrical connectors from resistor and motor.
8. Remove two heater case-to-dash panel attaching nuts from engine compartment.
9. Remove heater case support bracket-to-cowl top panel attaching screw from passenger compartment.
10. Remove one heater case bracket-to-dash panel screw, then carefully remove heater case from vehicle.
11. Remove heater core access cover, then the heater core and seal from case.
12. Reverse procedure to install.

With Air Conditioning
1. Remove instrument panel. Service and Repair
2. Remove evaporator case as described under ``Evaporator Case, Replace.''
3. Remove heater core access cover attaching screws, then the access cover from evaporator case.
4. Lift heater core and seals from evaporator case.
5. Remove seals from heater core tubes.
6. Reverse procedure to install.