Alright i have a 2000 chevy s1- no one in GM could answer this for me so i'll try it. my Pressure Cycling Switch on the side of the condensor (the silver canister deal ont he side by the battery) went bad (its already been trouble shot down to it) and i need to replace it. my question is, when i start to unscrew this thing is there a valve type deal on the back of it OR am i going to have to sit there for 10 mins taking it off slowly b/c i'll be losing ALL of my a/c.???? i've ask a few people and i'm 50/50 right now on wethere i'll lose it or not