Ok so i have recived several different answers on this

I have the old r-12 sytem that doesnt work. I am thinking of purchasing the retro fit kit from autozone to put r-134a into it. Some people said that plain wont work. Some said you have to vacum out the old stuff first and it will. Some said it will never work. What should i do? (besides rolling down the windows i hate that answer)

Thank you

 

It will definitely work if you do it right. There are instructions on the box and a bunch of articles and videos on-line. Google/Bing it. You'll probably want to replace at least a couple of parts (orifice tube and drier). Read first.

 

I definately disagree, the stock R12 system will cool very poorly at slow speeds and only provide ample cooling at highway speeds when using R134a. The condensors are constructed wrong for R134a and too small, the cooling fans inadequate, the orifice too large, and the pressure switch adjusted wrong. Fix these short comings and it will cool well.

 

What exactly do you disagree with? Doing it right, following the instructions, reading the articles, watching the videos or replacing necessary parts? Whether it's worse than, as good as or better than original is another issue. DIY is cheaper up front than a professional conversion. You just assume the risk.

 

The orifice tube should be swapped and a new drier would be a good idea. After the adapters are put on then a put a good vacuun on the system for 20-30 min. Fill with the proper amount of 134a and should be ok. One thing to keep in mind is that 134a runs at a higher pressure so if the compressor is weak it will not last long at all. I do not remember for sure but I believe it would take 75-80 % 134a as compared to r-12. The compressor oil may or may not be compatible with 134a. 134 a is a lot smaller molecule than R12 so any leaks from R12 will be magnified.

 

The cycling switch needs adjusting too. 1/4 turn? Can't remember which way. I read it somewhere. Google?

 

It runs at a higher head pressure for a given temperature and does not release heat as well as R12. You would need a condensor with roughly 1.5x the surface area to get the same cooling as R12. No amount of orifice tube or cycling switch adjustments is going to help the loss of cooling you are going to experience around town. You need to update the condensor to a modern style condensor and run more powerful dual electric fans from a LT1/LS1 car.