Repair 7

How to Replace the Heater Core in a 1991 Honda Accord

The heater core in a vehicle resembles a small radiator. When you turn on the heat in your car, engine coolant is redirected from the engine to pass through the heater core before heading to the radiator. The fan in your car blows the air over the heater core to heat it up. The air then flows into your car, warming the passenger compartment. In the 1991 Honda Accord, the heater core is located inside of the heater assembly, which is located behind the dashboard of the vehicle.

Instructions

1

Remove the cables from the battery to disconnect it from the engine. Drain all of the coolant from the cooling system into a sanitary container by removing the plug at the bottom of the radiator. Make sure the engine is cool before removing the coolant.

2

Remove the heater hoses going to the heater by loosening the clamps that are holding them on at the firewall. Remove the cable that is connected to the heater valve. Watch out for residual coolant that may be left inside of the hoses.

3

Take off the duct cover on the bottom of the heater assembly by prying out the snap-in screw with a flathead screwdriver. Remove the dashboard and the support pipe.

4

Remove the heater assembly by unbolting the four bolts holding it in and pulling it out. Take off the cover that is covering the heater core, and the clamp that is holding the heater core in place. Pull the heater core out of the heater assembly.

5

Insert the new heater core into the assembly and replace the clamp and heater core cover. Reinstall the heater assembly in the vehicle by placing it in its old spot and replacing the four bolts holding it in.

6

Reinstall the dashboard and the duct cover on the bottom of the heater assembly. Make sure you reconnect the heater hoses at the vehicles firewall and tighten their clamps accordingly. Replace the cable going to the heater valve.

7

Add the coolant back into the radiator making sure that it is full before starting the vehicle. Reconnect the battery wires and start the vehicle. Let the vehicle warm up to test the newly replaced heater core.