How do you replace your heater core on a 1993 Mazda protege?

Answer 1

The A/C system must be discharged and the evaporator removed in order to service the heater core on these models. It is illegal for anyone to vent A/C refrigerant into the atmosphere. Refer tofor information on the A/C system.

1. Take the vehicle to a EPA certified repair facility and have the A/C system refrigerant recovered.
2. Disconnect the negative battery cable.
3. Drain and recycle the engine coolant.
4. In the engine compartment, disconnect the A/C lines at the firewall by removing the fitting fasteners.
5. Disconnect the heater hoses at the firewall as well.
6. Remove the instrument panel and dash assembly.
7. Detach any electrical harness connections or cables from the heater and cooler units.
8. Remove the cooler unit-to-firewall attaching nuts and pull the unit backwards and remove it.
9. Remove the heater unit-to-firewall attaching nuts and remove the heater unit.
10. Place the heater unit on a bench and separate the heater case halves by removing the fasteners (clips, screws and/or bolts).
11. Remove the heater core from the case half.
12. Installation is the reverse of the removal procedure.