[DeTomaso] R 12 conversions

[Thomas Tornblom]

When I bought my car the A/C was empty.

It had a "new" compressor, from Hall I believe, as the old York had seized.

I had it converted to R134a, and it worked great for two seasons. The 
third season it was empty again.

They tried to find the leak, but failed, and they filled it up again.

The story repeats, worked fine for two seasons, and then empty again.

I then replaced all the hoses and had the shaft seal replaced.

On the trip to Le Mans in 2006 we were driving through Germany and ran 
into heavy rain, and as it was warm and very humid, we needed the A/C to 
keep the windscreen clear. Then we heard a loud bang, and the cabin was 
filled with smoke! It turned out that the hose to the expansion valve 
had opened at the fitting, dumping most of the charge into the cabin.

It turned out that the pressure switch on the drier was only a low 
pressure switch, so the pressure became too high and the hose popped.

We replaced the switch with a dual switch, which cuts the compressor 
also on high pressure. We replaced the fitting and charged the system 
again. This time it worked just that season.

Being fed up with having essentially a non working A/C I bought a leak 
detector on Ebay, and quickly found that the compressor appeared to leak 
everywhere.

I bought a brand new Sanden 508 compressor and I'm now into my second 
season  on that, and it still works great. I hope this will be the end 
of the issues.

Only a few weeks ago I read an article that said that many old R12 spec 
compressors have seals that will not work for long with R134a, and it 
appears that my old compressor was such a unit.

If I ever need to open up my A/C system again I will install a front 
mounted condenser.

Cheers,
Thomas

2010-09-01 10:15, Charles McCall skrev:
> Boyd -
> Others have more or less answered you, but the R12 to R134 conversion is the
> most common conversion around, since R12 is getting more and more scarce and
> expen$ive.
>
> When I bought my GT5-S, all the hoses were apparently in good shape and I
> had the system charged with R12. It all promptly leaked out. I had the
> system charged with R12 again and a dye to detect where it was leaking from.
> It apparently just evaporated, as they were unable to detect the source of
> the leak.
>
> So I decided to replace all the hoses and compressor and change over to
> R134. The DeTomaso vendors sell hoses with the proper fittings, but it may
> be easiest to have the same shop that is doing the conversion do the fitting
> change. That way if there is a problem, it is 100% their responsibility and
> they can't point the finger at outside parts and say that it isn't their
> fault.
>
> The process you describe is the general process for converting to R134 -
> change the fittings, purge freon, clean all the old stuff out and charge
> with R134.
>
> Remember that you should change the dryer just because while you have the
> system open...
>
> Charles McCall
> 1985 DeTomaso Pantera GT5-S #9375
> "Raising Pantera Awareness Across Europe"
> http://www.poca.com/index.php/gallery/?g2_itemId=2323
> -----Mensaje original-----
> De: detomaso-bounces at realbig.com [mailto:detomaso-bounces at realbig.com] En
> nombre de boyd casey
> Enviado el: miércoles, 01 de septiembre de 2010 0:36
> Para: De Tomaso List
> Asunto: [DeTomaso] R 12 conversions
>
> Hi everyone. Someone told me about an alternative  for R-12 refrigerant. One
> was supposedly based on Propane )LPG).  My local mechanic also is
> advertising  a service that modifies your system to be able to  use R 134.
> They claim to purge the system of R12 , changing the fittings and then
> purging all the  freon and using a combination of oil and other chemicals to
> completely   remove the old chemicals and replace them with R 134A ( after
> purging the system). They claim that this will allow your system to work
> without any other modification or replacement of parts (like the
> compressor). Is anyone familiar with this type of conversion or the use of
> substitutes for R12?. I have not tried to charge my system since I bought my
> car ( approximately 3 years) I have several cans of R 12  and I have no
> signs of any leaks in the system. The car was sitting for several years
> before I bought it. The previous owner was deceased for some time prior to
> my purchase of the car.. The owner owned an auto parts business and  an auto
> salvage business. He apparently was sick and out of commission and unable
> to  use the car much while he was sick.  Prior to the onset of his illness
> he apparentlty spent allot of money at Hall Pantera.  He had lots of Hall
> products installed ( stainless steel water tubes, Hall big bore headers and
> mufflers,  stainless steel fire wall cover , pressure bottles and over flow
> bottles. He also had several years worth of several year old Hall sales
> materials.. It doesn't prove anything but I would be inclined to think he
> had it functional. So ow that I have the car running with a degree of
> reliability I would like to have the AC functioning. If there is a way to do
> it that is less expensive then replacing the compressor I would be inclined
> to try the alternatives first. So any advice is welcome.
>
> Boyd
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-- 
Real life:   Thomas Törnblom             Email:  Thomas.Tornblom at Hax.SE
Snail mail:  Banvallsvägen 14            Phone:    +46 18 32 31 18
              S - 754 40 Uppsala, Sweden  Cellular: +46 70 261 1372