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R134a retrofit

Discussion in '80-Series Tech' started by cruiserman, Mar 22, 2004.

  1. cruiserman

    cruiserman

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    I foolishly let an AC shop retrofit my '93 fzj80 with R134A a while back. IIRC they replaced my leaking compressor with an ND reman unit, and they replaced the receiver/dryer. My AC is not currently working, and I suspect the POS reman is leaking. The performance was not very good compared with the stock R12 setup, and I'm wondering if I should replace the R12 condensor with a later model R134a unit.

    1, will this make the system cool better?
    2, will this force me to move the receiver/dryer to the unprotected location on later rigs?
    3, anything else I would need to replace to replicate the stock r134a system?

    tanx, eric
     
  2. fj55-100

    fj55-100 SILVER Star

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    No it will not cool any better with a 134 condenser, it is just an heat exchanger and dosent know the differences in gas
    134 in a retro fit does not cool as well as 12. the proprities of the gas are different it takes 134 longer to cool down the cabin but it still will git the job done ,
    one trick is to change the expansion valve , as they wear , and the retrofit may have introduced forgin material into the orifice
     
  3. Koffer

    Koffer

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    All remaned pumps are built with the upgraded parts for R134 (seals etc)

    I have done R12 to R134 (myself) to both my fj60 and my 92 fj80 and it has been working very well for the last 3 years . I didnt have any leaks that I could find but I was having trouble with the cooling . Took the trucks to a A/C shop and had then remove the R12 (they did it for free :D as its worth its weight in gold to them ) I then took it back to and got a vacuum pump and let it run for an hour . you could see the moisture bubbling up out of the drier though the window for most of that time . I reloaded it with the O ring conditioner, oil charge and R134.
    The TSB on the change is replace drier, add oil and paint the drier window black (if there is one as they dont come like that anymore )so you cant see the bubbles of the old oil as it will look like its not filled enough.
    I would looking into haveing a dye trace added to the systenm (if not already in there) and have it recharged and find the leak and work from there :cheers:
     
  4. lagwagon

    lagwagon

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    I did an r134 conversion on a 93 and it felt the same or better than before. I changed all o-rings, receiver-dryer, flushed it, expansion valve, and installed a NAPA reman compressor due to a bad compressor. One trick with 134 is you need to vacuum down the system for as long as you can stand. I also recall the possibility an expansion valve made for the conversion. The system is 3 years + old and still works great.
     
  5. cruiserman

    cruiserman

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    Thanks for the replies. The reason I asked about the condensor is that I think it is larger (and thus better able to cool). There are also different part numbers between the R12 apps and the R134a apps (6/93 and later).

    I'll find another shop to work with. I hate this crap. Damn Bush to hell.
     
  6. sjpitts

    sjpitts

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    I disagree with FJ55-100-- I think the newer condensor will make a difference. My understanding of the issue is that that R134 has a different temperature/pressure curve from R12, and that the result is the need for a larger (or more efficient) condensor in a R134 system-- if everything else in the system is equal.

    It makes sense to me. I know that it is what Vintage Air claims. They have a bunch of stuff about it on their website-- but it probably has to be viewed with some skeptisim since they are clearly trying to sell their Supercooler Condensors.

    Also, if it makes no difference, why did Toyota switch to a larger condensor when they switched from R12 to R134?

    I would think it would be worth a shot, given that R12 just continues to escalate in price.

    You could also consider adding a second condensor in series with the original, but I am not sure about that.

    Jared

    I should add that this really only addresses the problem of "not getting cold enough". If you are not getting cold at all, then you have clearly have other issues that are probably not related to condensor size.
     
  7. cruiserman

    cruiserman

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    Right. The AC is dead, but before I fix the leak, etc., I want to see what other parts I can change out for better performance. It appears many parts were changed in 6/93 with the change to R134A, but I don't know how many are required to get better performance. Perhaps I'll get a condensor and expansion valve and see what happens.

    I hate having a bastardized system and not being able to charge it myself.
     
  8. medtro

    medtro

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    [quote author=lagwagon link=board=2;threadid=13514;start=msg125081#msg125081 date=1079972083]
    I did an r134 conversion on a 93 and it felt the same or better than before. I changed all o-rings, receiver-dryer, flushed it, expansion valve, and installed a NAPA reman compressor due to a bad compressor. One trick with 134 is you need to vacuum down the system for as long as you can stand. I also recall the possibility an expansion valve made for the conversion. The system is 3 years + old and still works great.
    [/quote]

    Can you please tell us which components did you flush and how you flush them? Did you use alcohol or any special solvent?

    Should I flush the R12 compressor too if I have a good running R12 compressor for conversion?
     
  9. lagwagon

    lagwagon

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    I used a flush setup from NAPA which uses a canister that you fill with the chems and fill with compressed air. This is not always neccessary unless your compressor fails IMHO. Always replace the reciever/drier and most retrofit kits have adapters to R134, o-rings, and esther oil, which is compatible with R134 and R12. When you have a shop remove your R12 you can check the amount of oil removed. The biggest prob is guessing how much oil is in the reciever/drier, compressor, and the rest of the system. I have had good luck every time with my 60 blowing 42 degrees in 100 f ambient temps with the original compressor.
     
  10. cruiserman

    cruiserman

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    Any thoughts on going back to R12?
     
  11. Eduardo96FZJ80

    Eduardo96FZJ80

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    With all things considered, I really miss the R-12 system from my previous crusier (FJ-62) in comparison to the FZJ80.
    I have also heard that an electric fan helps, when in traffic, with little or no air flow, the A/C is almost unoticable.