Changing AC Pressure switch under pressure?

[Twisted99]

Can this be done or must it be evacuated. I have a new switch for the ? discharge one right next to the rad/overflow bottle. Noticed a set screw in the switch should this be left alone or tweaked. Thanks

 

[Ishodu]

The cycling switch, you just twist it off, there is a shadier valve under it, you may get a tiny piff but thats it. Good idea to change the O-ring too when you change the switch. My replacement came with a new one.

 

[clindahl]

Correct, the pressure switch can be changed without evacuating the system. Why are you changing the switch though and wondering about the set screw? Since you have a 1995 your car came w/ 134a, so there SHOULDN'T be any need to adjust the pressure. When I did a conversion on my 1993 from 12 to 134a, I backed the pressure down a little bit from what looked like 25 to about 20 PSI before it cut out, makes things nice and cool

 

[Twisted99]

Not changing the freon.....just had the new switch sitting around and changed the clutch/coil so....I stuck in the switch...