Larry,

I too had issue with Prevost concerning upgrading (What they called it) my R12 system to R134a. You should be aware that your system component sizes were designed for R12 and will operate differently with R134a. How much differently is for one with more knowledge of AC systems to answer. I wanted my systems to operate at maximum efficiency, so I stayed with R12.

It was ridicules what the quoted price was from Prevost. I saw they did not want to do the work, so they quoted a very high price. Remember, your system will not operate in the same manner as before a refrigerant change.

My fix was to repair my existing systems to a leak free status. It was easy. I pressure checked the bus air system, CC Bus Air, and found my leaks were on the compressor. It apparently had gotten hot at a time in its life. The reason was one of the condenser fans was not working. Replaced both condenser fans, replaced the leaking compressor, pressure checked the system with nitrogen at 250 PSI and leak free for 3 days. Recharged and all has worked for the least three years.

On my dash air, I did replace several hoses in the rear of the coach that was exposed to engine heat. Again, checked for leaks, now all OK.

AC work is not magical. It does require some work, but is doable. Also, POG member John Kloop is an AC expert and has helped me on an occasion through phone calls.

Concerning purchasing R12. I have purchased R12 from Ebay. The last 30 pound cylinder was $430. A 30 pound cylinder will last a very long time.

The key is to establish a leak free AC system before charging.

I searched for the post where I documented the work I did on my AC, but not success.

Regards,
Hector