K1500 ac problem
 

So, let me start out with the basics

112K miles
brand new ac system
(condensor, compressor, and lines) didnt change the accumulator this time because it was replaced right around 80K miles.

i go to fill it with the freon, and works PERFECTLY fine, but the moment it shuts off, it leakes at the line at the bottom of the condensor that runs into the fire wall, I called Chevy and they told me the specific sized o-ring, and torque to make it. So I did that. Still leaks. What else could be wrong? Any help is greatly appreciated. I spent litterally $200 on freon trying to problem solve.