How do you evacuate an automotive air conditioner system?
To evacuate the system, you will need a refrigerant recovery
machine. These cost about $3000 and usually this is best left up to
a shop, and to just evacuate, they won't charge you very much. I
think they should do this for free if they're not charging it too
since this is the equivalent of them charging you to take your used
motor oil. Technically you could just hook up a fill hose to it and
not connect anything to the other side, but this is against EPA
regs and you will be fined big time if caught. I don't recommend
this, it's very harzardous to breathe in R134 or R12. Also if
you're going to do this and open the system, you will have to do a
deep vacuum with a venturi or equivalent type pump to get all the
air out. I hope this helps with your project.