AC Question r12 to r134b possible?


the car is an 88 honda accord. The ac originaly was filled with R12. That stuff is gone, leaked out, escaped etc. Is it possible to recharge it with this newer stuff r134b, will it harm anything, the system needs to be flushed out completely or just get a can of r134b and fill it up?

thank you


you will need to buy a retro kit, the kit will give you instructions on how to change it over to 134.


Yes it can be done. As mentioned there is a conversion kit.

Fix the leak, replace the receiver/drier, install the conversion kit then evac and recharge with R134.

I recommend having a professional do the job. A/C repair work is not really a DIY job.



r134b is not the same as r134a. it(r134b) is as toxic and unsafe as r12 was, so the question should be r12 to r134a. which with todays technology can be done with a very simple kit from the local parts house.


For what it’s worth, I got a kit at WalMart for about $30 and converted my 1987 Mazda 626 a few years back. I tightened a loose hose and the conversion was still working two years later when I donated the car to charity.


This is a simple conversion and i personally have done at least 12 of them over the years. The key to success is making sure you pull a good vacume on the system. This will get as much of the old oil and stuff out of the system as possable. It will also make sure you are starting with a “clean” slate. I purchased a vac pump that hooks up to my air compressor for $60 out of one of the mags, and it does a fine job.


It’s easily done but the car is 20 years old and has lost all of the refrigerant charge.

You must repair the leaks first or you’re just wasting time and money.


Yes you can “convert” R12 to R134a (not R134b), but you probably want to talk to someone who is familiar with your car’s AC system first. R134 is less efficient than R12 and may not give the same performance, depending on the size of the condenser and evaporator. I tried converting one of my cars (professionally) and was not happy with the performance, so I converted it back to R12 (much better). Also, R134a operates at higher pressures and is sometimes tough on compressors that were originally designed for R12. Whatever you do, have the system leak tested and evacuated before attempting to recharge it (with a new drier installed). You are usually better off having AC work performed by a qualified shop anyway.


Yea also use a direct R12 replacement which is more environmentally safe and more effecient. Its called Duracool (R12a- I believe)/ check the site on the internetand buy direct. I do not believe local auto stores have this.

Have converted 4 cars and trucks so far.

Good Luck