Genuine Mazda MX-5 Miata Heater Core

Mazda MX-5 Miata Heater Core Parts and Q&A

• Heater Core
  NE51-61-A10
  Q: How to replace the heater core on Mazda MX-5 Miata?

  A:

  For 2005 and earlier models, begin by having the air conditioning system discharged and recovered by a qualified repair facility. Disconnect the cable from the negative battery terminal and drain the engine coolant. Remove the center console and the instrument panel, then unlatch the seal plate latch on the right side of the heater unit. Disconnect the heater hoses from the heater core by undoing the hose connections at the firewall, using towels or rags to catch any dripping coolant. Remove the three nuts from the studs retaining the heater unit to the firewall and take the heater unit out, which will include the seal plate as an assembly. Next, remove the heater core from the heater unit, and reassembly is the reverse of removal, ensuring the hose clamps are securely positioned when installing the heater hoses on the heater core. Refill the cooling system and have the air conditioning system evacuated and recharged at the shop that discharged it. For 2006 and later models, start with having the air conditioning system refrigerant discharged and recovered by a qualified repair facility. Disconnect the cable from the negative battery terminal and drain the engine coolant. Remove the flange bolt securing the air conditioning lines to the evaporator at the right part of the firewall, disconnect the lines, and discard the old O-rings while plugging the open pipes to prevent moisture and contaminants from entering the evaporator. Loosen the hose clamps and disconnect the two heater hoses from the heater core pipes next to the air conditioning lines on the firewall, again plugging the open pipes. Remove the instrument panel and the fasteners securing the air distribution unit and the air conditioning unit to the firewall. Separate the two units by removing the two nuts that secure the air distribution unit to the air conditioning unit. The heater core is located in the air conditioning unit, so set the air distribution unit aside and disassemble the air conditioning unit by removing the fasteners that secure the upper part of the housing to the lower part and then take off the upper part. Finally, remove the heater core from the lower part of the housing, and installation is the reverse of removal. Refill the cooling system and have the air conditioning system evacuated and recharged at the shop that discharged it.