Is it possible to convert the coach a/c using the R-12 refrigerant into the new R 134-A system?
SASSY1, you didn't say what model and year Lazy Daze you have (those are good things to add to your signature), but for what it's worth, in 2001 I had my 1985 LD's cab air conditioner converted to use the newer refrigerant. It cost me $1,100 back then; probably would cost more now.
Yes you can change systems. An A/c professional must evacuate the existing system and capture the old gasses. Then the old valve must be replaced with a size that will accept the new refrigerant because it’s a different size. Some shops will still fill it with R-12 but it is very expensive. You’re better off changing over.
Beside changing the valves to 134A quick disconnect valves, the system must be totally flushed with a specialize cleaner to remove the R12 PAG oil , it is not comparable with the new 134A PAG oil that needs to be added with the new refrigerant.
It’s a big project that will not cool as well as the original R12.
Larry
Thank you all, much appreciated...it was for a '93 model that I was considering to purchase, I've since decided not to buy that unit and will continue to look for my "one"...that I know it's out there :-)...safe travels...