Heater Core
 

So, my heater core is shot and I know I can replace it. I am just afraid of taking that dash apart and losing some of the pieces due to age and being brittle. SO, my question is, has anyone tried the stop leak/liquid aluminum to stop their heater core leak? If so, what are your recommendations. I figure, it can't hurt at this point to at least try it before I rip everything apart. I'm in El Paso, so having heat is not a big deal, but I know it would affect resale of the car, plus those 2-3 days of really cold weather we get it would come in handy!

I wouldn't want to gunk my engine up with that crap. I think the heater core can be removed without removing the dash.

If you know how, I'd love to hear it! I'm not afraid of taking the dash apart, per se, but, just don't want the really old parts to break cause I know most likely, I can't replace. Just trying to avoid a bigger problem if I can.

I don't think you need to mess with the dash to access the heater core. The heater box is located under the dash compartment below the dash itself and is easily accessed from the passenger side, especially with the seat out. You don't want to even think about removing the dash, this is a very major job and yes, it's likely things would get broken in the process.

As far as damaging parts while removing the heater box, as long as you're careful with the air ducts and make sure to locate and remove all the mounting screws before pulling the ducts out it all should go back together pretty easily. You'll also have to detach the control cables to the box. The heater box itself mounts to the firewall with 3 10mm nuts, as I recall, pretty simple.

There is one weak link in the system to watch out for however. It's the resister coil on the blower motor housing next to the heater box, as I recall. Be careful not to disturb the resister, it's very fragile. If you break one of the coils your blower motor won't work and you'll have a problem you don't want. It looks like this:

Attachment 748481

I don't think you can find a replacement coil new and used ones are nearly unobtanium.

I have a couple heater cores in my aluminum recycle bin, if you need one let me know, free for the price of shipping.

Or:
could you just route AROUND the heater core, by detaching the 2 external fire-wall hoses and connecting them directly, in the engine compartment? Take the core out of the cooling path. Won't immediately stop your core leak till it dries out (maybe some compressed air into one of the firewall inlets will get some clearing thru?...)

Stu Aull
80GS
AZ

Core is already bypassed when I bought the car.

Regarding fan resistor, I managed to find one for my REPU by searching for 1975 Ford Courier parts. It looks identical to that one you shared a photo of.

and failing that they all work the same, so pretty much you can use any old one, i'd try the Rx8 first though, looks really similar