Heater core replacement

[vangremlin]

So right in the middle of a cold snap a couple weeks ago my heater core sprung a leak and started dropping bright green coolant on my passenger footwell.  Because I needed to keep driving the car and had to order in the new heater core, the first thing I did was get a 5/8 to 3/4" adaptor, pull the hoses off the heater core and join them together using the adaptor.  I now had a car, but no heat.

I pretty much followed Jurjen's excellent write up in the Eaglepedia, and have a few comments below based on my experience.  My car does not have A/C, so it may be different for those cars.

- There are three spots where the heater box attaches to the firewall, two by the fan opening, and one right behind the valve cover.
-  My car had four cables that attached to the heater box: fresh air vent, amount of heat, heat on/off, and defrost.
- I ran into difficulty pulling the box out because the bottom caught on the carpet, and also on some wires I had installed for some additional lighting. 
- When reinstalling the box, it was helpful to get it kind of lined up from the inside, then go to the engine compartment where you could reach in through the fan opening to further align the box and pull it forward.
- Getting the bolt through the hole that is right behind the valve cover was the most difficult.

The basic process went pretty smoothly.  The things that slowed me down included making new foam seals for the box (the weatherstripping I bought from Lowes must have been old because it was impossible to get the backing paper off in one piece), one of the cables popped out of the clamp holding it to the heater controls so I had to pull the radio pod out to put it back in place, and, when re-installing the radio pod I broke the ground wire off the glovebox switch, so I had to solder that back together.

I did this swap at the same time as I installed a new radiator.  Once I got the new radiator in place, I fired up the car - no heat  .  But I followed Jurjen's directions to pull the top hose off the heater core to bleed out the air, and now all is well.  Nice warm car, just in time for the 14 degree temps and snow tonight.

After I was done, I found the following link in one of anrkii's posts, which gives additional helpful info:

http://www.skidmore.edu/~pdwyer/amc/eagle/heater.htm

Here are a couple pics:

Not to hard to spot where the leak was coming from



Old vs New.  You can see the new one isn't as wide as the old one

[IowaEagle]

Glad the job went well.   I sure miss the old days when AMC heater cores were easily accessible from under the hood.

[vangremlin]

Glad the job went well.   I sure miss the old days when AMC heater cores were easily accessible from under the hood.

I was talking about that with someone yesterday.  It would make life so much easier if the heater cores were under the hood, and not just on AMC's!

[IowaEagle]

I did one on a Ford once where you had to remove the passenger side fender.  Talk about fun.  At least I was working in a service station (yes, there were service stations that actually fixed cars) where it was warm and we got paid by the hour.

[vangremlin]

I just wanted to give everyone an update.  Yesterday was the first day I really took Pepe out for some driving.  That new heater core works fantastic.  Even on the 3 mile drive to work, I was already getting warm air out of it, whereas before it was still freezing cold.  Its not a fun job to swap the heater core, but with results like this, its well worth it.  I may have to start driving with the windows down even in the winter 

[eagleman]

Just sent you a thumbs up for a job well done! Thanks for sharing.

[IowaEagle]

GREAT!

[Amc1320]

Heat is good!

Mine takes forever to get warm, hope its not my heater core going bad!

[IowaEagle]

The Concord is anemic.  I hope it just needs a good back flush.  Nothing leaks, now.

[mudkicker715]

The Concord is anemic.  I hope it just needs a good back flush.  Nothing leaks, now.

Might want to try a good burping first. It worked inmine plus its rambler mentality

[IowaEagle]

The Concord is anemic.  I hope it just needs a good back flush.  Nothing leaks, now.

Might want to try a good burping first. It worked inmine plus its rambler mentality

Its been burped, and everything else is happy.  I think its just a plugged up core.

[mudkicker715]

Ouch that is gonna hurt

[IowaEagle]

I am afraid when I backflush the leaks will appear.  Will just try with plain water at first.  Those chemicals do not like 34 year old parts.

[mudkicker715]

Are we certain its not the rad cap. The one on my ford 150 gave me everything i could think of  meaning all was replaced than i replaced the cap again. It now seems towork as of today. It stumpped me and he guys i trust. Just a fyi

[vangremlin]

Just sent you a thumbs up for a job well done! Thanks for sharing.

Thanks!  This is one of those jobs where its easy to get apart, and hard to get everything back together.  Which is good, because once you get it apart, you have no choice but to put it back together!!!