Situation - I had to replace the condenser so I pulled the fans, radiator, and condenser. Replaced it, and then put everything back. I lost the o-ring for the top oil cooler line going into the radiator, so I bought an o-ring kit from Autozone, replaced the o-ring and attached everything.

The fitting(at the threads) is leaking. I've unscrewed it and double-checked everything at least three times. I don't know what to do. Bigger o-ring? Plumbers tape? .

I FINALLY have ice cold a/c, but I'm leaking trans fluid when I drive. Pretty much defeats the fun.

TIA
Nick