Aircon - R12 and alternatives. What to do?

Discussion in 'Engine' started by br1anstorm, Mar 14, 2007.

  1. br1anstorm

    br1anstorm Active Member

    Messages:
    95
    Joined:
    Mar 14, 2007
    Location:
    Scotland
    Car:
    1990 Mercedes Benz 560 SEC
    I have three pre-1992 cars - including my W126 560 SEC - with a/c systems running on R12. I'm hoping that as long as I run the a/c periodically to keep the circulation going and the seals lubricated, things will be OK. But I fear it's inevitable that re-gassing will be necessary at some point, and my instinct is to prevent, or anticipate problems rather than wait until something fails.

    Ideally I'd like simply to have a 'top-up' of a tiny quantity of the existing R12 (the least polluting option...?). But I believe that's impossible or illegal (at least in the UK). Second option is, I gather, to use other refrigerants (R24, or others?) that can be added to, or mixed with, R12, and which are compatible with existing seals, compressor, etc. Are they any good? Any downside?

    The third (nuclear!) option is to convert to R134a. New seals, compressor and Lord knows what else. On a W126 that could cost arm and leg and more.

    I've browsed other threads like this one
    http://www.mbclub.co.uk/forums/showthread.php?t=31177&highlight=R12+aircon
    but still can't decide. Is it better to do nothing until forced to convert when the existing a/c fails, or bite the bullet and do it sooner? And what is the Mercedes "kit" for converting to R134a: is there one for each model, what do they consist of, what cost, and can independent specialists obtain and fit or is this a dealer-only exercise?

    Any comments/advice would be welcome...

    br1anstorm
     
  2. compress ignite

    compress ignite Hardcore MB Enthusiast

    Messages:
    208
    Joined:
    Jun 4, 2006
    Location:
    32 degrees North by 81 degrees West
    Car:
    '90 300D 2.5
    You will not be happy with the results of any of the "Snake Oil" confabulations that purport to
    replace R-12 in performance and efficiency.
    AND some of them are down right hazardous (Propane or Methane mixtures!)

    R-134 conversion is possible [BUT you must remove ALL traces of the R-12 (Mineral based)
    lubricant.]
    The R-134 lubricant is synthetic and the two are not combinable.
    In addition the "O" rings and the Receiver/Dryer must also be replaced.

    To provide the same level of cooling capacity,the condenser should be replaced with a Parallel
    Flow condenser(30 percent more efficient).

    Only install 75 to 80 percent of the original volume of refrigerant when converting.

    'Much more is involved...this just a basic overview.
    "GOOGLE" shop forum and search a member's posts named GSXR He's covered the subject.
     
    Last edited: Mar 15, 2007
  3. Harley Man

    Harley Man Hardcore MB Enthusiast

    Messages:
    346
    Joined:
    Aug 17, 2006
    Location:
    Cranleigh, Surrey
    Car:
    CLK W208 ragtop, C250TD Sport, and loads of motorbikes
    I have been told that you can still get your AC recharged with R12 in France, a friend of mine has a Citroen Masarati and that was the advice he was given. :)
     
  4. Roger Jones

    Roger Jones Hardcore MB Enthusiast

    Messages:
    825
    Joined:
    May 18, 2006
    On the other thread I said:

    I had my W124 300E turbo converted to 134a with the Retro-Pro conversion kit (a US product) by:

    http://www.aircool.biz

    It's now been running for seven months, with no problems. I paid £50 (+VAT) in addition to the normal regassing price.
     
  5. Glenn Smith

    Glenn Smith Hardcore MB Enthusiast

    Messages:
    369
    Joined:
    Mar 7, 2006
    Car:
    2000 c230k estate
    I placed a thread in the above, i did some research into converting from r12 to 134a, by rights you should replace the oil and the receiver drier, however i read some details posted by an american guy who had been doing it the way i did the 300se (ie fitting adaptors and refilling with 80% charge of 134a) he reported that he had had no come backs directly related to modifying in this way. As for changing the seals, why bother they will probably not leak (i know from experience, when we first changed to 134a, our supplier forgot to tell us we should be fitting different seals, no problems there) changing the oil may well be a good idea, but is time consuming due to having to remove components and draining them, i have also tried mixing the different oils and they seem to mix ok, not like mixing brake fluid with engine oil for instance more like mixing mineral and synthetic engine oils.
     
  6. Sp!ke

    Sp!ke Administrator Staff Member

    Messages:
    12,234
    Joined:
    Jun 2, 2002
    Location:
    West London
    Car:
    SL500 & The Fart Car
    Just take a driving holiday to eastern Europe and they'll fill you up with R12 no problem.
     
  7. OP
    OP
    br1anstorm

    br1anstorm Active Member

    Messages:
    95
    Joined:
    Mar 14, 2007
    Location:
    Scotland
    Car:
    1990 Mercedes Benz 560 SEC
    Aircon - what to do?


    Clearly this discussion tends to prompt input from both the principled and the pragmatic.!

    Thanks to both members above for their very practical suggestions. (Glad to know France may be an option: I go there periodically but I had thought the ban on R12 was EU-wide).

    br1anstorm
     
  8. Stratman

    Stratman Hardcore MB Enthusiast

    Messages:
    4,597
    Joined:
    Jun 15, 2003
    Location:
    Sunbury
    Car:
    W203 C200 CDI '04Estate
    Have a look here

    The whole site is worth browsing as well.
     
  9. Glenn Smith

    Glenn Smith Hardcore MB Enthusiast

    Messages:
    369
    Joined:
    Mar 7, 2006
    Car:
    2000 c230k estate
    Very good site and one that i came across when doing some research into the subject along with many others.
     
  10. Glenn Smith

    Glenn Smith Hardcore MB Enthusiast

    Messages:
    369
    Joined:
    Mar 7, 2006
    Car:
    2000 c230k estate
    I would guess they fit the R134a charge ports and refill wthout any other mod, these port adaptors cost about £4 each trade, all you do is remove the old valve core (after recovering any remaining gas) and screw the adaptors on.
     
  11. OP
    OP
    br1anstorm

    br1anstorm Active Member

    Messages:
    95
    Joined:
    Mar 14, 2007
    Location:
    Scotland
    Car:
    1990 Mercedes Benz 560 SEC

    Thanks Stratman and Glenn... I agree with you both: a clear and commonsense site written by someone who knows what he is talking about. If only I lived in Kent, I'd have him check out the a/c in all three of my cars!
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.