I have a 79 24ft excella 454. The A/C clutch was bad so I replaced with a rebuilt A-6 compressor. before mounting I fillled
the compressor with the recommended amount of r134a compatible oil and purchased a r134a conversion kit (basicly the adaptors that screw over the schrader valves also remove the old valve core before screwing on the r134a quick release adaptors. This system was designed for R12 refridgrerant
so to fill properly you install 80% of the r12 capacity so if the system holds 5 oz of r12 multiply that by 80 % and install that much r143a refridgerant and it will work. R134a is not as efficient as r12 but it ain't 260 bucks for a 20 lb can either. My dash is
pumping out 40 degree F air consistantly. It won't freeze you
out of the camper but I have been cool enough to not be sweating also some
12v fans can help distribute the air around the coach. You should be able to get rebuilt A6 For around 100 bucks, the conversion kit from 20 to 30 bucks, and the reciver dryer for about 25 or 30 bucks at napa jobber. now before the system can be charged you have to pull a vacume on the system
to remove all of the air you let into the system when it was dis-assembled and you may also want to check the system for leaks before installing refridgerant if the system holds the vacume it should be ok. Be sure not to overfill the system with r134a as this will cause the system not to cool at all. if you don't have a vacume pump you could re assemble the system and then take it to a a/c shop and save some $$ by haveing alot of the repair work already done the a/c tech can then pull a vacume verify no leaks and then recharge the system with r134a and you would be cool again wouldn't it be great to be COOL again ? Just my 2 cents worth !
Frank S
79 excella 24ft
83 310 under restoration