AC problem and what system?

[AviatorD]

Ya one of those is my switch. It looks like the 850 a/c pressostat switch. Would I just unscrew the thing and replace it with a new one? Do I have I have to worry about the hose it's connected to, such as it being under pressure?

[Ozark Lee]

I have not had to replace one yet on any of my Volvos but the ones I have replaced on other cars had a Schrader valve below the switch so it was simply a process of unscrewing the old one and screwing the new one on. You will get a slight pfft of coolant purging but it is nothing to worry about.

...Lee

[AviatorD]

Hey all, I just ordered a pressostat switch for my car. I hope this is the fix to my problem. I was wondering if I could just unscrew the old pressostat switch and replace it with the new one? In regards to ozark lee's comment, does the volvo 850 glt year 1996 have a Schrader valve where the pressostat switch is located? And how can I determine if it does have a Schrader valve, so that I can look for it on other cars?

Much Thanks

[AviatorD]

Ok, I just attached the new pressostat. Now my a/c will turn on, but now I have another problem :/ The compressor will cycle on and off. About 2 to 5 second intervals of on and off. Does that mean that I have a leak in the system? If the leak isn't big enough, could I just charge the system and then look for the leak after this California summer? My wife hates the heat in my car.

Thanks

[JRL]

Short answer yes.
Charge it and see what happens

[1911colt]

Mine was doing the same thing, turns out I needed to shim the compressor clutch, now everything is great!!!!

[AviatorD]

Do you have to remove the engine to get to the compressor or can it be pulled from under the car? And also, how much of a clearance do i need for the shim?

Thanks

[jblackburn]

Not at all, you can get to it from under. Most need <.05" taken away from the gap. About the thickness of the tab on top of a can of soda.