GM Truck Club
Founded in 2004 ~ We're the #1 Chevy Truck & SUV Forum.
Silverado & Sierra | Tahoe & Yukon | Suburban & Yukon XL | SUV & CROSSOVER
Results 1 to 3 of 3
  1. #1

    Default R134A retrofit Q's

    Just got a 93 sierra . 4.3L with 5 speed. Like the truck so far. But the AC doesnt work. The PO suggested recharging the system.

    Then I realized it was r-12. I would like to just recharge the system with r-12 and see how it works. But it could be compromised in some way.

    Please advise...and if you think a retrofit is in order.

    What all needs to be done for a retro...???

  2. #2


    It's very difficult to buy R-12 nowadays (unless you're a licensed A/C tech, but even then it's expensive).

    I converted my sister's old '86 Chrysler Laser from R-12 to R-134a. I didn't notice much difference (technically, R-134a is less efficient). The kits nowadays contain the special oil and fittings to make the conversion happen.

    I have a 20-lb bottle of R-12 and the gauges, but I still wouldn't use it unless it was for a classic vehicle where originality counts. For everything else I use R-134a.

    The basic steps to convert the system are...

    1) Find (and fix) the leak
    2) Replace the accumulator (the dessicant inside to absorb moisture 'wears out' and should be replaced).
    3) Add the proper amount of R-134a oil (comes with the kit).
    4) Install the conversion fittings (also from the kit).
    5) Evacuate the system with a vacuum pump (very important step! If you don't get the air out, you can't fit all the refrigerant you need and it'll never be as cold as it should be).
    6) Add in the specified amount of refrigerant.

    If you don't have the parts and refrigerant, you might be better off contacting an A/C specialist and seeing how much they would charge to do the conversion.
    Norwalk, CT

  3. #3


    What Kirk said, but to add, you need to flush everything out of the system before adding the 134 oil. From what I understand, the 12 and 134 don't play well together. Wouldn't hurt to replace the orfice tube while you have it apart. Good luck

    99 K 1500 Suburban
    78 Silverado Big 10 w/factory 454
    00 S-10 Blazer
    1976 Trans Am
    1980 Honda CB900 Custom

Similar Threads

  1. AC retrofit
    By mary in forum Chevy Suburban Forum (GMC Yukon XL)
    Replies: 0
    Last: 04-05-2010, 11:25 AM
  2. A/C repair/retrofit
    By gofish in forum General Chevy & GM Tech Questions
    Replies: 0
    Last: 11-26-2009, 06:10 PM
  3. 2007-2009 yukon retrofit air cabin filter
    By robert61 in forum Chevy Tahoe Forum (GMC Yukon, Cadillac Escalade)
    Replies: 0
    Last: 08-15-2009, 07:26 AM
  4. Factory Tow Mirror Retrofit?
    By northerndoc in forum Chevy Silverado Forum (GMC Sierra)
    Replies: 8
    Last: 04-20-2009, 09:09 PM
  5. Mirror compass retrofit question
    By Hummer in forum Audio, Video & Gadget Tech
    Replies: 3
    Last: 06-10-2008, 01:06 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts