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

 

If it's a pressure switch I would say that the back side of it is directly in the freon. you might get luck and end up with a diaphram. When you unscrew it slowly, if you here some freon escaping I would say to tighten it back in and go to your service ports for the A/C and let the freon out there, it's a schrader valve ( like a normal tire). If you let the freon out slowly your oil in the system won't be let out and you'll just need to have the A/C re-charged, if you go to fast the oil gets decompressed quickly and vaporizes with the freon and you loose it. Having to re-oil the system will be extra $$$.

 

well a guy told me if it does let everything out majority of the oil will stay int he system and told me to put in 1 can of 134a that has oil in it, and another can that doesn't ahve the oil in it to replenish what was released

 

thanks i guess i'll find out tomorrow when i buy the switcha nd start unscrewing it...

 

it is diff on some applications. when you get the new one look at it and you can tell. you will not need to add oil unless you are replacing the reciver drier/accumulator. but it should be brought under vac for like 15-30 min

 

+1 usually they go on top of a valve.....

 

If you were replacing R12 with R134 I could see that, but why in this situation?


Other than that I agree with most people that have posted.

 

Mars- Gotcha! But would that really be necessary on a '00? I am well aware of a/c systems taking a beating, but really?