Air conditioning leak?

Hi, I have a 1992 325i. After being not having run the car for about 3 months last winter the a/c stopped blowing cold. I had the system pressure checked and it was 0 all around. From what I've read I suspect the compressor shaft seal dried out while it was parked. The shop that checked it out wanted to waste a can of r-12 to test for the leak, and then replace the compressor and their estimate about 1,200 was too high i thought. How can this be tested without wasting precious r-12 to leak test the system? If my suspicions are correct should i replace the compressor or can i just have the seal replaced? Also is it possible to have the system charged with recycled r-12 and could that be cheaper? I'd prefer not to convert to 134a if possible. I live in a very hot climate and not having a/c killed me last summer.

__________________
This post was auto-generated based upon a question asked on our tech article page here: Pelican Technical Article: BMW Air Conditioning Maintenance and Upgrade

[Wayne 962]

You should probably take the car to a shop that specializes in A/C systems. They will be able to evacuate any freon left in the system, and then fill it with a special fluid / dye that they will be able to track with a special detection lamp. Then, they will fix the leak (probably an o-ring or seal as you suggested), and then they will pressurize the system again and leave it pressurized for several hours or a day. Then, they will check to make sure it's holding pressure, and only then will they refill with R12.

- Wayne