Replacing a heater core in a Volkswagen Passat is not an easy task and not for the unprepared. The heating/air conditioning assembly is located behind the instrument panel, and the entire panel must be disassembled and removed in order to reach the core.
Unplug the cable from the negative battery terminal. Make sure you have the radio's anti-theft code so you can program it after reattaching the cable.
Drain the Passat's cooling system, disconnect the heater hoses from the core and discharge the air conditioning system. Use clean containers for the coolant and refrigerant.
Disassemble the instrument panel. Remove all covers, bolts and screws, electrical connectors and components, including the radio, center console and glove box.
Remove the ventilation ducts and the heater/air conditioning housing assembly. Remove the heater core from the assembly.
Install the heater core into the heater/air conditioning housing assembly. Reinstall the assembly and the ventilation ducts.
Reinstall the instrument panel, steering wheel and air bags. Reconnect the heater hoses to the core, fill the cooling system and connect the battery cable. Evacuate, charge and leak test the air conditioner.
Start the Passat's engine and let it reach normal operating temperatures. Check over the climate control operation and check for any leaks.
