Faustus on Capmaster’s site has this question, I’d like to repost it here to help him out:

Faustus:
Ok I suck at cars, thats my dads area but apparently he has no idea what this part is called and I need it to get my AC fixed.

Its a 1999 Mazda 626 2.0l.

Let me do a horrible mockup.

Its basicly a bolt that has a little thing in the center that LOOKS like an alan wrench would go in it (though it doesn’t appear to be what was intended.

My dad says its on the “High side line” and as far as I can tell its job is something stupid like releasing excess pressure you overfill the freon (just a guess by me really) whatever it is it leaked all my freon out and now I have no AC… In TEXAS… IN THE SUMMER!

Anyone have a clue what part this is or what part I have to buy to get said part? So far dealer shops around here have NOT been very helpful.