[W126 Coupe] Air Conditioning Issues

[Dick Spellman]

Hi Cal:

There remain HUGE proponents of R-12.  Obviously our MB systems were 
designed for R-12 and will no doubt be happier if we continue to use 
it.  R-134 presents higher head pressures and from the many complaints I 
have heard on this and other lists, poorer quality cooling.  I've not 
experienced a problem in any of the MB's I've converted and drive with 
R-134.  However, I have experienced a really bad performance more than 
once in rental cars or SUVs while traveling on business in the southern 
US.  It has taken longer to demonstrate any cooling effect, longer to 
cool down the passenger compartment and in one instance never cooled the 
SUV in my opinion (the later was a Ford SUV POJ that I got stuck with 
from Budget or whatever in Boca Raton, FL last July)  So, there is 
plenty of evidence to support the fact that R-134 does not and can not 
work as well as R-12.  But, where I sit in Boston there is ONLY R-134 
readily available.  I am convinced that with the right set-up and care 
in making the conversion you can be cool and quickly in a Mercedes.   I 
have never experienced in a MB what I have so many times been dealt from 
new car Mfg's poor quality in the rental cars I am saddled with driving.

So, go with what you can get (12 or 134) and hopefully you'll stay 
cool.  I am fearless about recommending R-134 in Mercedes based on my 
limited experience thus far.

Dick

malcolm369 at comcast.net wrote:

>Hi Cal,
>
>In addition to the other good advise posted, Here's what I did, finding a leaking man/hose on a well functioning ACC.
>
>I did have the slightly leaking manifold hose replaced with OEM NOS (old stock). The first one came through with rust inside one of the hoses. (1 day extra) A fresh OEM hose was installed, along with new MB o-rings.... filled with R12 (Cold) thank you.
>
>No drier/expansion valve, etc. replaced. ACC working fine & seemed a bit weak only. The drier (in round numbers) will saturate in about 20 minutes with a hose broken or unsecured. If the system is cool (or so) you're probably fine to leave it alone. (seat of the pants prior A/C training & shop experience here) your mileage may vary.
>
>OEM Part: $398.............  Aftermarket: $179!!!
>
>I don't know. If an aftermarket hose is designed for more modern R-134 refrigerant, won't it be better with the larger molecule R-12? I don't know.
>
>I think I'd replace it with an aftermarket hose today.
>
>The refrigrigerant & sundries are pretty standard......... the hose is the biggie.  WOOF!
>
>Hope this is of assistance.
>
>MBL
>
> -------------- Original message ----------------------
>From: "Calvin Young" <calvinyoung at cox.net>
>  
>
>>My last visit to the dealer advised that my air conditioner manifold hose is
>>leaking.  Anyone have  any experience with replacing this and want to share
>>their experience.  How much is the hose, better to repair than replace,
>>replace the receiver dryer at the same time, etc.
>>
>>Cal
>>
>>
>>The MB Coupes Website!
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>>Postings remain property of MB Coupes, L.L.C.
>>    
>>
>
>
>The MB Coupes Website!
>W126 SEC Mailing List
>Postings remain property of MB Coupes, L.L.C.
>
>  
>