On my 69 vert, I had a garage do the a/c about 18 months ago. System is empty again, so will find the leak. I want to covert the system back to R12 and have 3 cans on hand.
I know I need to purge the system and remove as much moisture as possible and this can also help me check for the leak. Many sources say to replace the Dryer and can do that.
Would you then add oil first, and then the R12? Curious about the proper sequence.
Unfortunately the oil is throughout the entire system. To convert back you would need to remove all the lines and the valve on the firewall. The compressor also would need to be removed. The drier needs to be removed and replaced. All the lines can be flushed with alcohol and then blown dry with compressed air. The valve needs to be cleaned on both sides with alcohol. The evaporator and condenser need to be flushed and dried. The compressor too.
Then it can all be reassembled. New oil compatible with R12 can be installed, along with a new drier. I like to vacuum the system for 8 hours before installing any freon. Some folks prefer 24 hours.
Thanks Royce. Sounds like a job. May need to get a mobile mechanic to the house!
The oil is the issue between R134 and R12 which do not mix. So like was mentioned you have to flush it all or replace components. Most everything can be flushed except for the accumulator and R134 condensers(dependent on type)
Did any components get changed over to R134 when the conversion was done or did they simply swap refrigerant?
Its not uncommon to be underwhelmed with the cooling efficiency going from R12 to r134, especially when just swapping refrigerant and. Or a system designed for 134.
In the future is suspect we all will be discussing how to convert R134 over to the new replacement of R1234!
They did not change anything except for the dryer, which I am changing again. I am also changing out the valve at the fire wall. and you sort of nailed it. It never worked well at all. So trying to get back to what I know will work.
With the factory ac parts you will be happier with r12 for sure.
R134 can work well too with the appropriate parts of course but it’s always more then just flushing and swapping refrigerant types