Evacuating an AC system question

[57larry]

I need to replace a trinary switch on a fully charged AC system. I don't have a way of evacuating the system without it going into space like the old days. Anyway I can make a sucking system or should I just let it flow?

[papastoyss]

I need to replace a trinary switch on a fully charged AC system. I don't have a way of evacuating the system without it going into space like the old days. Anyway I can make a sucking system or should I just let it flow?

Do you already have the new switch? Some vehicles have a valve in the fitting for the switch to prevent gas loss when replacing the switch. If it's an aftermarket system probably not so. I'm not advocating just let the gas fly but I realize it happens a lot.If you do loosen a line to relieve pressure do it slowly to prevent loss of oil.

[57larry]

already have the new switch, it's Vintage Air

[rooster]

I need to replace a trinary switch on a fully charged AC system. I don't have a way of evacuating the system without it going into space like the old days. Anyway I can make a sucking system or should I just let it flow?

I haven't done it but i is being done!

http://forums.maxima.org/general-maxima-discussion/317690-recovering-r-134a-refrigerant-c-cheap.html

[enjenjo]

A Vintage air Trianary switch should be on a 1/4" service port with a Schrader valve in it. Break the valve loose, after about to turns to remove it, it will stop leaking because the valve will seal up. To double check, look in the mounting port on the new switch, there should be a plastic pin in the center, flat on the end.