AC pressure transducer - schrader valve behind it?

[paramax55]

I'm about to change my AC pressure transducer. The pictures of the new one make it look like it has a nipple to depress a schraeder valve... is there a schraeder valve behind it? Or do I need to evacuate the system? I can recover the refrigerant and dump it back in, but it's obviously quicker and easier If I don't have to.

 

[chopperman1]

No to schraeder, need to evacuate.

 

[paramax55]

For anyone doung this in the future... I pumped the system down (to 10 psi) and there was a valve behind it. It leaked like the seal was gone and it was metal sealing metal, but the valve was there. It would have been a pain if I hadn't pumped it down.