1. Welcome To GMTruckClub.com!

    The #1 Chevy Truck Forum Online
    Online since 2004, we are the #1 Chevy Truck & SUV forum and user community. If you have any questions about your Chevy or GMC Truck, SUV or Crossover, or just want to connect with other GM owners and enthusiasts around the world, you've found the best place on the internet to do that.

    Join Today ~ It's Free
    Registering is Free and Easy! Hope to see you on the forums soon!

R12 to 134a conversion

Discussion in 'General Chevy & GM Tech Questions' started by 1991 Suburban, Apr 2, 2011.

  1. 1991 Suburban

    1991 Suburban Rockstar 100 Posts

    Okay, it is starting to warm up, and I have decided that this year, I want my a/c to work properly.

    My '91 Sub is the old R12 system, what I want to know is how difficult and expensive is it going to be for me to convert to the 134a?

    Thanks!
  2. MightyMax

    MightyMax Rockstar 100 Posts

    Pretty easy and straight forward....
    They have kits for it.

    You just have to stick on the new connectors and put in the R134

    The oil in the system may be the only thing that may cause you problems.....
  3. 1991 Suburban

    1991 Suburban Rockstar 100 Posts

    Yeah, I have looked it up online, but everything is pretty vague. Do these kits include something to flush the old R12 out of the system? I know you aren't supposed to mix the two refrigerants, but what would happen if I don't get the system flushed properly? I just don't want to spend the money to convert the system and end up screwing it up...
  4. dpeter

    dpeter Rockstar 3 Years 100 Posts

    I have switched several vehicles from the 12 to 134A, two of mine and seven others and the only time I experienced a problem was with a system that had been opened and left open and had gotten moisture in it and anyones guess what else. Most had very slow leaks or bad compressors and/or leaky seals. Most kits I have used ranged from 25 to 40 dollars and come with good instructions and enough refrigerent for most conversions. I am obligated to urge you to reclaim and dispose of the R-12 in accordance with EPA requirements. Take it to a shop and have them reclaim it or if the system is flat then no prblem and go for it but be sure to pull a good vacume on the system. Follow the instructions and you'll be cool.
  5. Chris Miller

    Chris Miller Rockstar 100 Posts

    It's also a good idea to change the accumulator and orifice tube.
  6. 1991 Suburban

    1991 Suburban Rockstar 100 Posts

    Luckilly, my system seems to be sealed (still has pressure in the lines), but don't really know if my compressor is good. It definitely engages (feels like my Sub drops a couple of cylinders when I turn it on!), so I assume it's still good. Thanks for your help.
  7. dpeter

    dpeter Rockstar 3 Years 100 Posts

    I would agree with Mr. Miller if there has been a history of leaks and refills as air and moisture can surely cause you problems. In your case it probably is not needed but the tools for the connections are not at all expensive and niether are most parts and o-rings. On the bright side, once you've converted then there is no longer a requirement to recover the refrigerent you are using and you can get the 134A without a liscence and it is available every where.

    I see you are in California and you guys are real sticklers about pollution so you may want to verify the last statement I made about the 134A as there may be a more strict standard than the feds have.
    Last edited: Apr 2, 2011
  8. 1991 Suburban

    1991 Suburban Rockstar 100 Posts

    Yeah, California just switched from 134a to 134ca, which is the same thing, except instead of the puncture top, they are now self sealing tops, which require a special adapter which costs another $6, then you have an additional $10 core charge for each can, so that the state can reclaim the 8-10% most people don't get out of the can...
  9. Chris Miller

    Chris Miller Rockstar 100 Posts

    I recommend the accumulator mainly because the R-12 mineral oil lubricant isn't compatible with R134 and could cause some issues when you put the synthetic PAG oil in.

Share This Page