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R-12 to R-134a retro conversion

Discussion in 'The Garage' started by K5Chris, Apr 23, 2004.

  1. K5Chris

    K5Chris 1/2 ton status

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    anyone done it? what's it take?
     
  2. 4xcrazy

    4xcrazy 3/4 ton status

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    I have, i installed the new valve and freon in my system, it works, but not nearly as cool as the factory or r-12 setup. If you want it to be cool like the newer vehicles do from the factory, you will need to install a new condensor (in front of the radiator) designed to run the 134 freon, more cooling area. I priced on of these units and was told they are about $150 or so. In my book thats not too bad.
     
  3. Smitty

    Smitty 1/2 ton status

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    Changed mine 4 years ago. I ended up replacing all the components because just about everything was missing when I started. Mine cools great but I didn't have the R-12 working in the Blazer to compare before and after.
     
  4. K5Chris

    K5Chris 1/2 ton status

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    it cooled real well last july when i took the clutch off cause i pulled the motor out, and i never got around to tightening the clutch down until today. it kicks on, and cuts off after about 2 secconds.

    i'm debating on weather to pay someone to put a couple cans of R12 in, or, just go ahead and convert over. i know i'm going to have to pay someone to evacuate the whole system, but, i can do the conversion and buy whole case of 134a at sams club for like $1 a can, and put it in myself. last time i checked, R-12 was going for like $50-55 a can.... i have the R-12 gauges and everything to put R-12 in, i just don't think i can get my hands on any cans.
     
  5. 4xcrazy

    4xcrazy 3/4 ton status

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    The 134 only conversion works great, /forums/images/graemlins/waytogo.gif if you are constantly moving, /forums/images/graemlins/frown.gif but when you stop at lights or idle for a minute or so, it warms up a bit, depending on the outside temp, like out here in the middle of summer when it's 115 out, my AC when it warms up is at a temp of about 85 degrees, granted thats cooler than out side, but it's just not performing like it's supposed to. Temps should be down around 40ish or so is what i was told.

    The newer 134 condensors, i found out, have more and smaller cooling tubes, so the freon has more time to cool off, will also prolong the life of the compressor getting the freon cooler before it heads back in the compressor.

    Mine does work better when i had the extra electric fan blowing on it when the compressor kicked on, but not like newer factory setup.
     
  6. 4xcrazy

    4xcrazy 3/4 ton status

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    If your system is still sealed, try out the stuff called "Hotshot" you will probably only need alittle bit of it, and my friend Paul (pauly383k10) put some in his and works fine. The Hotshot is compatible with r-12 to go right in with it.
     
  7. 55Willy

    55Willy 3/4 ton status

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    local parts house should have the kit to swap it over, none of the other parts need to be swapped exept the valve, which is included int he kit.

    the kit will vary between 30-45 depends on who you go to, wally world has em too.
     
  8. K5Chris

    K5Chris 1/2 ton status

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    thanks for the info /forums/images/graemlins/waytogo.gif

    would it cool better with dual electric cooling fans instead of the belt driven one?
     
  9. gm4x

    gm4x 1/2 ton status

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    I believe they make a "drop-in" replacement that only requires evacuating old refrigerant & simply a re-charge with the new stuff. I'd check into it before dropping the $$ for a bunch of other stuff. I didn't do auto A/C, but I know they make a direct replacement for R-12 in refrigeration. For some reason, the brand name of Hot Shot comes to mind /forums/images/graemlins/dunno.gif
     
  10. 4xcrazy

    4xcrazy 3/4 ton status

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    [ QUOTE ]
    thanks for the info /forums/images/graemlins/waytogo.gif

    would it cool better with dual electric cooling fans instead of the belt driven one?

    [/ QUOTE ]

    I simply had the motor driven fan still running, i added a 12" pusher fan on the outside of the condensor, yes it did help somewhat, but it still warms up with low engine idle and less air flow.

    Like i said, if your system is still sealed, throw in some of that Hotshot, that will get it cooler again, no need for evacuating the system, it's compatible.
     
  11. pauly383

    pauly383 Daddy383 Staff Member Moderator

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    [ QUOTE ]
    I believe they make a "drop-in" replacement that only requires evacuating old refrigerant & simply a re-charge with the new stuff. I'd check into it before dropping the $$ for a bunch of other stuff. I didn't do auto A/C, but I know they make a direct replacement for R-12 in refrigeration. For some reason, the brand name of Hot Shot comes to mind

    [/ QUOTE ]

    They do make drop in replacement. Its called hotshot generically. The actuall name is r414a. I sell this at work , I get it from Whirlpool. You charge it like r-12 but only use 80 percent of the r-12 charge. So if you used 10 ounces of r-12 , you'll use 8 ounces of r414a. I can get it with a friends license, but couldn't ship it. If you go to Napa they have a generic version called freeze 12, you could use that and leave the system set up for r-12. Hope this helps /forums/images/graemlins/thumb.gif /forums/images/graemlins/k5.gif
     
  12. Triaged

    Triaged 1/2 ton status

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    [ QUOTE ]

    i'm debating on weather to pay someone to put a couple cans of R12 in, or, just go ahead and convert over. i know i'm going to have to pay someone to evacuate the whole system, but, i can do the conversion and buy whole case of 134a at sams club for like $1 a can, and put it in myself.

    [/ QUOTE ]

    I bought a venturi vacuum pump from Harbor Frieght for $14, adapted it to the r134a connector and evacuated my system myself. All you need is a good compressor that isn't going to die from running constant for 30-45min (mine got real hot!). There is a post somewhere about my conversion...
     
  13. K5Chris

    K5Chris 1/2 ton status

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    [ QUOTE ]


    I bought a venturi vacuum pump from Harbor Frieght for $14, adapted it to the r134a connector and evacuated my system myself. All you need is a good compressor that isn't going to die from running constant for 30-45min (mine got real hot!). There is a post somewhere about my conversion...

    [/ QUOTE ]

    where does the refridgerant go?
     
  14. Pookster

    Pookster 1/2 ton status

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    You can do the conversion- Its not too bad-

    New REceiver dryer.

    Evacute old system.

    Put on R134 heads.

    wait if you can, to see if vacuum drops inside system. If you cant, just put in the r134. Check the lbs of r12 the systme needed originally.

    Anyways, I finally (after a year) put in insulation. Wow, what a difference. I basically covered the *WHOLE* AC line (cool side) with pipe foam. If you look at the second gen k5's, they use a lot of exposed "aluminum" sections, which, in GM's infinate wisdom, it is located right on top of the return (hot)side. Hence, your loosing a lot of cooling just to the underhood temps. Im gonna find something to insulate my whole receiver, since that thing is always icy cold! No point in cooling down my engine bay!
     
  15. K5Chris

    K5Chris 1/2 ton status

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    i picked up the new fittings w/ o rings at orilleys for $10. it said it had an extra fitting for '91+ GM's. i dunno if mine has it or not. the regular fittings were like $6. i have the hose/gauge, and i think i'm gonna buy a case of 134a at Sam's Club. is there anything else i need? what's this reciever dryer?

    i think the shop said they'll charge me $20 or so to evacuate my R12. that sound decent?
     
  16. Thunder

    Thunder 3/4 ton status

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    A case of 134A /forums/images/graemlins/eek.gif /forums/images/graemlins/eek.gif
    You only need about 5 8oz cans(40-42OZs) to recharge a Blazers system. You use less 134a than freon. If you over charge the system you will destory your compressor.
    The reciever/dryer is the silver can. You should replace it if you are converting. It can be contaminated with water or contain the old oil. Which is not compatable with 134A.
     
  17. unclematty

    unclematty 1/2 ton status

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    not to be a jerk but why bother with power robbing ac, in a 4x4 any way? thats what windows and removable tops are for. /forums/images/graemlins/thinking.gif /forums/images/graemlins/hack.gif /forums/images/graemlins/weld.gif /forums/images/graemlins/grind.gif
     
  18. Pookster

    Pookster 1/2 ton status

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    I was gonna say something, but then I realized,

    that if you can live out in UT-
    1. without shade
    2. Without AC in your truck

    /forums/images/graemlins/bow.gif DAMN.

    Im a wuss. /forums/images/graemlins/smile.gif I like AC! A lot!!!

    [ QUOTE ]
    not to be a jerk but why bother with power robbing ac, in a 4x4 any way? thats what windows and removable tops are for. /forums/images/graemlins/thinking.gif /forums/images/graemlins/hack.gif /forums/images/graemlins/weld.gif /forums/images/graemlins/grind.gif

    [/ QUOTE ]
     
  19. 87sm465np208

    87sm465np208 1/2 ton status

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    i bought the 34$ kit autoscoan sells, i put it in my 87' chevy V-10 system, dont know if a pickup a\c system is differnt then the pickup system but i as well never had it working with R-12 and figured that since i work outside all day no matter how hot it gets after work jumping in my truck and kranking the A\C on MAX and the blower on high it feels REAL good compared to nothing. /forums/images/graemlins/woot.gif /forums/images/graemlins/waytogo.gif
     
  20. K5Chris

    K5Chris 1/2 ton status

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    [ QUOTE ]
    not to be a jerk but why bother with power robbing ac, in a 4x4 any way? thats what windows and removable tops are for. /forums/images/graemlins/thinking.gif /forums/images/graemlins/hack.gif /forums/images/graemlins/weld.gif /forums/images/graemlins/grind.gif

    [/ QUOTE ]

    a. this is my daily driver
    b. i live in houston, texas
    c. i'm not drag racing, and i dont think i'm gonna notice the 3 hp loss
    d. the g/f's complaining is pretty convincing
    e. why not?

    /forums/images/graemlins/thinking.gif
     

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