R12 isn't illegal, it's just expensive also it's not really flammable per say but you can burn it and it will put off poisonous gasses but I think the others will burn too. It's illegal to make in the US so it's harder to get. If your system is in good condition and you used the green seals at all the fittings and you replaced your receiver drier with one compatible with R134a I'd say go R134a. Be sure that you have the system vacuumed out to insure there is no leaks. Darkstar -----Original Message----- From: Chris Hawes Subject: [DML] A/C gas types I am nearing the end of rebuilding my aircon system (evaporator blew) and wondering what gas would be best. 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/