Adding to Steve's comments, there is also an ethical issue associated with the use of sealers. Do you have the responsibility to tell a repair facility that you have used leak sealers in your A/C system if you go to them for repairs? I would say absolutely "yes."

Evidently, some shops are finding that these sealers are damaging their refrigerant recovery units and the manufacturers of these machines are beginning to void warranties if the machines have been used on a car that has been exposed to these sealers. See
System Sealers Void Warranty that says, among other things:

"Vehicles found or suspected of having an A/C refrigerant sealer in the system should be serviced as a refrigerant system containing a contaminate. Visteon approved refrigerant system flushing equipment/agents may not remove the refrigerant system sealer from a contaminated system, and replacement of the entire A/C refrigerant system is recommended."

Unfortunately, there's no such thing as a free lunch. I, too, have a 124 in a hot climate (Central Texas) and keep my fingers crossed on the evaporator. I, too, have considered using a sealer if the evaporator should develop a leak. However, I have decided that if a leak happens, I will bite the bullet and do the replacement myself. If that happens, while I'm working, I'm gonna try not to think about how quickly Steve and some of the other pros out there could do the job!

I agree about the recommendation of continued use of R-12 in a system originally designed for it. Those in the north will not understand, but every 1/10th of a degree counts down here in the south!

Also, I really do think that we've seen or are seeing the peak on R-12 prices -- there are simply too many shops that insist on converting incoming R-12 cars to R-134a. Now, where is that R-12 going? By law, it cannot be vented and a shop would be foolish to do so anyway, so this R12 is being recycled into the market (see this site for example). Couple this with those that are hoarding it and also consider the reduced number of vehicles on the road with R-12 and you have a classic case forming of supply eventually exceeding demand. Bodes well for those DIYers that want to stay cool . . .

Richard Easley
Waco, Texas