Fixing a refrigerant leak

What happens when a coca cola machine runs out of refrigerant? Is the leak repaired and new R12 (which is no longer manufactured) is put in or is a new (and different) refrigerant put in its place or is the compressor and new refrgierant put in? I'm assumming they would use R-134a. Does anyone else have this problem. I heard R-12 is very expensive. What is the costs to do this?

Thanks----------- Larry

[johnieG]

Well in general, it will start to over heat & trip the over- current protector cycling on/off every few seconds or so (if you are lucky, it won't damage the compressor, but it could in the worst case scenario, burn out/lockup the compressor) first; you would have to locate & repair the leak, second; R12 is still around, and yes it is pricey, next R134a (or R22) can't be used in an R12 system that is used for refrigeration as it isn't compatable with the older oils that were used, and the newer oils will damage the electrical windings inside a  hermetic/sealed system (unlike an automotive conversion which has a mechanically driven compressor) if the compressor is sound an the system is just low on a charge, then after the leak(s) are fixed it would  be recharged with an appropriate replacement for R12, (such as mentioned in the refrigeration section), R414B, R409, etc. you'd want to have the system checked by a professional. might want to give our friend Eric at Global compressors a call,

[audiobeer]

JG's advice as always is solid. Sometimes you may get lucky. I hade a dry cooler that would not cool. After 5 years of sitting around a local coke guy put a schrader valve and a shot of freon in it for $80. That was 4 years ago and it has run "not stop" without any problems. It may take another 40 years before the present load leaks out? I'd try that first. If it leaks out in the 1st year, I would switch it all over assuming that you plan on keeping it. I am in the process of restoring a R1 Coolerette with the same issues. I elected to switch it over and a Coca-Cola guy is doing it for $200.

Is there a test for the compressor to see if needs replacing (worn valves, piston rings, cylinder) prior to repairing the leak and charging with new  refrigerant? Do they go bad often. Mine make a low humming noise and I hear a little hissing in the refrigerant lines with little if any cooling. I'm assuming it's low on refrigerant and the compressor is ok, but I'd like a check if there is one.

Larry