Im replacing the pressure switch, and there was a rubber washer wrapped around the threads where the new switch would go. It doesn't look worn or torn up. The new one didn't come with one so can I just reuse the old one?

Thanks

 

To seal from leaks.

 

Just go grab an o-ring kit from hobo freight.

 

You'll want the correct one. They have to be AC friendly.

 

Are you referring to the O-ring or the switch?

 

The O-ring. Get a seal kit for your AC. A rubber seal will not last.

 

But that's what was originally in there, a rubber seal, as pictured

 

Unless you are a polymer chemist (which I actually am), "rubber" is used by folks as a generic name for all things that have the properties of what rubber things do.

There are o rings and other things made from rubber like compounds that have different chemical compositions which dictate their properties

The ones used in HVAC must not chemically react with the refrigerant or oil, and must be able to handle the pressures and temperatures in the system without shrinking, cracking, or otherwise self destructing.

So they make special o rings for HVAC, and the consensus is that you must use an o ring designed for this purpose.

Neither you nor I know from what material the previous one is made. So don't worry about the past

Concentrate on the future.

 

You think it's safe to assume it's the type you described since it's stock? I'm the first and only owner of the car so i know it hasn't been changed.

Either way I looked at it again a bit closer and it has a small tear in it so I will definitely be replacing it now. Will keep in mind what you said

Thanks!

 

I would indeed concur that the dude/dudette at the factory used the corect part.

Just make sure the o rings you purchase are listed for used in hvac, specifically R134a refrigerant