Hi Rod, According to the EPA, you must remove the R-12 before charging with another refrigerant: http://www.epa.gov/Ozone/snap/refrigerants/macssubs.html The debate on alternative refrigerants aside, I wouldn't worry about R-12 availability; at least, not right now. Despite the scare tactics that some MVAC shops seem to use (probably to sell you on a conversion), there is a TON of R-12 out there. Take a look on Ebay and you'll find a plethora of options every day, from 12oz. cans to new-in-box 30-pound cylinders. Travis (learning a lot about air conditioning and R-12 lately as I work on this system on my car) On Aug 15, 2006, at 4:50 AM, dmcnews@xxxxxxxxxxxxxxx wrote: > I noticed from an earlier post that some are using Freeze 12 to > replace R-12 in our origional AC systems. Are the two compatible so > that Freeze 12 can just be added to an R-12 system that is getting > low on refrigerant or does the R-12 system have to be evacuated > first? If so, does anything else have to be done to the system > before adding the Freeze 12? I have been fortunate and have never > had to add R-12 to my DMCH refurbished car in the 5 years I have > owned it. I plan to stick with R-12 as long as it is available if > I need to add refrigerant to the system. If R-12 becomes > unavailable is Freeze 12 a better alternative than 134a? Thanks, Rod [Non-text portions of this message have been removed] To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/