So, I had to tear the AC apart Sat. night. There was a leak at the expansion valve. Took about 3 hours, but I had it up and running, no problem - until I got into it today. It leaked again, from the expansion valve joint...unbelievable. I used red loctite on the joints, preplaced the o-rings and everything. Tightened the hell out of it, too. What else can I do with the damn thing? I really don't want to take it apart again, and I'm sick of messing with it. O'rielly's had this crap that you inject into the system that is supposed to seal of metal holes or leaks in the system - anyone use this stuff before? Will it chew up the compressor? Or is it worth a try? Should I just take it to a shop? (I know what everyone will answer here...) How do I go about finding one that I can trust to do the work right?