Trying to fix a heater core leak problem and need help. The old heater core was leaking, got it out and put in a new one and it is doing the same thing. On the outflow side the copper pipe from the old core is used in the new core and it has an o-ring on it and a U-shaped clip to hold the two flanges together. My question is is this: is there supposed to be 1 of the u-shaped clips or two? The old one only had one but it makes sense to me that there should be two. Could that be the problem causing the leak? Frustrated in Georgia.

 

there's only one; I had to swap that pipe over when I did my core as well

I reused the O-Ring, 'cause it was surprisingly still in decent condition, but that O-Ring COULD very well be the source of the leak...

what really sucks is that the only way to find out, is to tear the dash apart again

 

That's what I need to know. Fortunately, I did not have the dash back in so it won't take as long. Thanks for the reply.