I have a 1964 olds f85 deluxe and the heater core started leaking all over my brand new carpet I just installed. Does anyone know the proper way to take it out to replace? Do I take it out through the inside of the car? thanks.

 

The heater box comes out from inside the car as a unit. The bolts stick thru the firewall and the nuts are removed from outside at firewall.

 

If you don't have factory A/C this will be maybe 1 of the 2 times you'll be glad. There is one nut behind the passenger wheel well that's a bear to get. Once you get all the nuts off you remove the heater box from the inside. The heater core will come out with the box. It's stubborn so you have to work at it. Be careful because the firewall insulation at the top of the carpet is attached to the bottom studs.

You need to drain the radiator level down below the heater core, before disconnecting the hoses. I would get a very large plastic trash bag and spread it out on the passenger floor. Have a couple of bath towels handy because coolant will come out of it. I think it holds a quart.

Reassemble is reverse. Sometimes it requires another set of hands to get the tubes through the firewall while the person in the car reinstalls the heater box.

Proper cuss words apply!

The heater core should be available through your local parts store.

 

Depending on whether you have AC or not there may be more bolts to undo. The 65 should be almost identical to 64 and 67

 

You do not have to remove the bolts for the blower housing nor the blower. Just remove the flange nuts in the picture Allan posted.