1HZ AC to R134a

[Loober]

Hi,

My A/C is in need of a recharge and since its R12, I now have to convert it to R134. I was wondering what is needed to be changed, I've read that some change everything out, compressor, dryer, etc; others just charge it with 134 and use the existing components. One thing for sure is I'll need to get some kind of adapters for the ports on the compressor so the fittings to charge will fit. See attached photo of the top of the compressor, the ports face towards the block and air cleaner and do not allow much room to attach anything, what can you guys recommend.

Thanks

 

[zuker81]

My understanding is just charging it with 134 will result in even faster leakage (smaller molecule) if the existing refrigerant is leaking out, not to mention potentially rendering the system useless due to the way it interacts with the lubricant used for R12. Replacing the seals (or whatever is causing the leak) and adding R12 appears to be possible if you know where to get it (i.e. eBay or certain types of shops). I recently broke down and had a full conversion on my HZJ73 done... with 100+ degree days for a over month in Texas I could justify the expenditure. Research online made it sound like a royal pain to DIY the conversion. I'm sure someone has done it though, hopefully they can shed more light.

 

[roscoFJ73]

When I changed gases in my FJ73 , I had to change the dryer according to the air con shop, but it was cheap. I had new seals put in.
But They are not as good as the original gas they were designed for, maybe 90-95% as good, the shop warned me about that. Later on I upgraded the compressor to one from a HZJ7* and it was better.

 

[jblueridge]

The oil mixed in with the R12 is not compatible with R134a. There is an aircon oil that works with both or either.
It might be good to flush the system to get rid of the old oil.
If the system has not been used in a while, and it lost R12 somehow, you should think about replacing the o rings.