I put a new evaporators in my car but the gas leaks just behind the nut alnog the large Aluminum line. I used a new o-ring from Ray. What am I missing? It leaks right where my finger is pointing.

 

Nevermind guys, I solved the problem. You need two o-rings on the both side of the flange before you tighten the nut. Even though apparently the FSM does not show two O-rings. Save yourself some trouble guys if you replace the evaporator and use 2 o-rings.

 

What makes you think 2 o rings there in the ac line?

 

The leak was right where I was pointing to. There is a flange on the large line that has an o-ring on the front side of the flange (facing the evaporator). When I put an O-ring on the back side of the flange the leak stopped.

 

I think he is saying (and I agree) that flange is only meant to take one o-ring. I would guess that the first time around you had the o-ring twisted, knicked, or the wrong size on there.

 

I purchased new OEM O-rings from Ray so they could not be the wrong size. Upon removal there was no evidence of twisting or tearing. This video show the leak of Freon behind the nut that was solved by placing a 2nd o-ring behind the flange as well as in front of the flange.

 

It may work for you (for now) but if a 2nd o-ring behind the flange fixed your leak, then that means the first one isn't doing its job. The 2nd one just gave you a band aid.

 

The O-ring used was brand new from Ray.

The O-ring was OEM and brand new from Ray.

 

You can see the Freon leaking after connecting the evaporator to the low pressure line. Ugh! the video did not load...

 

The threads look damaged and have trash on them which could prevent full compression of the sealing o-ring the first time. Putting something behind the flange (an o-ring in this case) lets the nut push the male tube a little further into the female socket to compress the o-ring.

The second o-ring can not seal a leak path from behind the flange. If gas gets past the first o-ring it can just leak past the threads.