Hello! I am wondering if anyone has suggestions on the best way to isolate an AC Leak. I just filled it a few weeks ago, and now it is hot like a summer day again. I was told that the Ultra-Violet R134 doesn't work very well - does anyone else have opinions on that process? I was also told if there is a leak it would likely be an o-ring that needs replaced. Any suggestions or links to a good how-to would be greatly appreciated - thanks!