Just started on replacing the heater core in my 65 and honestly its pissing me off. It's been leaking during high revs and I cannot find the leak. I tightened the clamps but that didn't seem to help. So we ordered a new heater core and there aren't any directions.


Will it kill me if i just loop the hose for the time being in order to stop the leak?

 

There are 4 each 1/4-20 nuts in the engine compartment that hold the heater in place and a long sheet metal screw to the right of the heater along side the glove box. But first, make sure you got new hose and some new clamps. You got to disconnect the three control cables (move them and follow the sounds) and the electrical connector on the box inside and the two wires in the engine compartment as well. Cut the hoses. Pull the heater. BE CAREFUL OF THE DEFROSTER PLENUM, it's cardboard. By this time, you may have realized that it's cramped so next time remove the RH seat. To split the heater case, use a screwdriver NOT TO PRY OFF the clip but in the slot at the end to pull out the part on the box. Now I always buy a gasket kit because the car is 40 + years old so from here on you replace and reinstall. Route the uncut hose thru the two hose holes, attach and pull thru. Oops, you for got to note, bottom hose goes - uh, better make a note of that too. As this is sometimes a real pain in the - just cut the hose near the engine long enough to make a jumper, you can drive it then.
Jim

 

Haha Thank you Thank you Thank you. Looks like I'll deal with the heater business when it starts getting cold again.

 

Get what I listed for parts, do the hose jumper bit and most of all, have fun doing it. If you don't think it's going to be fun, think about doing something else not car related. Part of the owning of a classic is the upkeep.
Jim

 

Oh yeah definitely. I don't have the time though to start bigger projects. I play lacrosse which requires practice every day and games on the weekends. My dad works late most of the time and my brother plays baseball every day. We just finished all the weatherstripping which was a little frustrating but fun and dirty. I have prom coming up in the next couple weeks and I definitely want this to look great and not be in the middle of the projects/ or for it to leak haha.

 

Attention all owners of defective heaters - There is a how-to article in the May 2007 edition of Mustang Monthly. While you're at it, subscribe.
Jim

 

If I may..a couple of more suggestions. Before you install your new heater core and hook it up....you may want to test it. Simplest way to do this is toclamp on a couple of pieces of heater hose, and take it in the house to the kitchen sink. Fill sink and submerge the tank, then will holding your finger over the end ofone hose...blow into the other end...pressurizing the tank. Hold it under pressure for 30 seconds or so and look for bubbles. If none..you're good to go. If some...you just saved yourself a whole bunch of time.

The other suggestion is to consider a water cut off valve. Piping hot water through the interior adds interior heat, no matter how good the new foam gaskets seal. Most modern cars shut the water off. The photo below shows a plastic inline valve installed inline just before the firewall - that is vacuum actuated. It is a stock water cutoff valve out of a mid 80s Ford truck. In this case, whenever the engine starts, the vacuum pulls the valve closed, cutting off the flow of water to the core. In the winter, just unhook the valve and plug the vacuum line.Some go so far as to run the vacuum line inside under the dash so they can turn it off and on.

 

been there and done it solid advice from above posts to be sure,,,only suggestions is while everything is torn apart is ,,,think about what else might go out and be a major pain to replace it reguards to the heater box area..etc.etc,,,,second I've been thinking seriously of doing 2 things,, 1 an H valve to route water back to the motor in case ..just such a deal happens and the other is that since hoses go out more often or should be replaced every X number of years depending on where you live ( I'm in AZ and talk about engine temps ) take a new heater core to a welding shop and have them work up some extensions to the tubes so that they stick outside the fire wall and then when you have to replace the rubber hose you don't have to blitz the whole thing... just a thought

 

A bit of a different philosophy. When traveling thru the Arizona desert on I-10, I took advantage of the heater and turned it to defrost with the windows open to take advantage of some extra water cooling. It's a little uncomfortable, but at 110 F at 2 PM, I figured I needed a bit extra help.
Jim

 

I jumpered mine because it was leaking , like the 3rd day i had it, and its still jumpered... Im lazy.. and broke,, what can i say.