Re: [DML] my 134a conversion begins...

["Walter Coe" <Whalt@xxxx>]

Andy,

One thing that I seem to always hear about R-134a conversions is that they
do not cool as well as the original R-12. I understand that the main reason
for this is that R-134a requires a larger condenser than what comes with an
R-12 system. I heard a comment from someone a while back that one of the
DeLorean vendors is selling an increased capacity condenser specifically for
R-134a conversions. If anyone can confirm this, I want to know too.

> 2. what about the "A/C dryer" that some places have told me will need to
be
> replaced? i can't find anything on any of the vendor's sites that is
called a
> dryer. does the DeLorean have this part?

The "dryer" is an old term for what is now referred to as the "accumulator".
Since both the fuel system and a/c system have accumulators, the terminology
gets confusing.

> 4. does the line that goes from the accumulator to the evaporator need to
be
> changed?

I have heard an interesting story enough times that I suppose it is true:
When Mercedes first introduced R-134a as original equipment, they had
massive problems with leaks. It turned out that their prototype conversions
worked fine because the refrigerant lines were already 'broken in' using
R-12, but the new production cars with the same type of hoses seeped
refrigerant everywhere. From this the industry learned that new hoses had
to be specifically made to handle the smaller molecular shape of R-134a.
The type of hose used for R-12 was too porous for R-134a, but was fine for
R-12. However(!), once a hose had been used for some time with R-12 in it,
stray R-12 molecules would clog the pores enough so that the smaller R-134a
molecules would not leak out. The moral of the story: You can convert a
well used R-12 system to R-134a without changing the hoses. But if you use
new hoses, they need to be of the type that is not porous to the smaller
R-134a molecule.

My opinion on this is that if you had problems with the other OEM hoses
leaking R-12, then it is a given that they will leak R-134a even worse. I
would be concerned that your evaporator hoses would not be any different.

DMC Joe is an avid believer in using a drop in R-12 substitute called
Freeze-12. I think it costs around $15 for a 12 oz. can and cools as well
as (not worse or better than) the real R-12. I saw a shelf full of cans of
the stuff at a local import specialty parts store. The owner swore by the
stuff. People say that it is not flammable and can be topped off and still
not become flammable. The store owner told me that it is not legal in some
states and there are issues with importing/exporting it.

I am certainly no authority on any of this stuff, so if anyone wants to
correct me or confirm any of this, please do so. I'm only going by what
I've heard and not from any manuals or text books.

Walt Tampa, FL