Herb, those were not 'my' statements.. they were in the question to Redfox about his judgment on those issues..
I do not know either to be true for sure... but on the first I am leaning from what all has been said to believing that Duracool is better than 134a.
I have said that I do not know enough about the criteria to ask critical questions which might point out something important to the comparison.. hoping that someone else WITH this kind of technical knowledge will jump in and say ' yes that counts" or "no, something else is the deciding factor"....
My basic position comes from reading what I have been able to find about ac systems... that is why I have an appreciation for R-12 ...but with that goes an appreciation for following the other rules when servicing it....
I have to trust that others here will read close enough that they understand that the misrepresentations, personal attacks, and silly statements like " I can get the proof , but why bother" are very suspect activities when it comes to defending something where the physics of the item are the basis for analyses of its merits or drawbacks....

gsxr

All CFCs,HFCs and HCFCs can produce hydrochloric or hydrofluoric acid when they are in the presence of moisture that is why you have driers built into the systems. Some are more reactive than others. the reason people don't like pag or poe oils is that they absorb moisture not allowing the drier to contain it. Mineral oil does not absorb moisture that is why we had very little problem with our a/c systems for so many years.

redfox,

My position? That's a good question. I have worked for software companies for fifteen years and various areas of electronics instrumentation for about the previous fifteen years. My positions in my industry have varied from engineer to technical marketing positions.

My hobby for most all of my life, certainly all of my adult life, has been anything automotive.

I am by nature an experimenter and modifier, but there are certain core principles that I don't experiment with, especially when it involves a component that has been proven by many, MANY years of successful service. I have never been one to argue that the sun rises in the East and sets in the West.

gsxr,

I have seen a few components eaten up by R12 in a system that was not properly evacuated without a good filter drier. R134 is even worse in this regard.

My Dad had an independent auto repair business most of the time I was growing up. In about 1956 he went to a class and started installing a/c in customers cars and doing a/c service work. I can remember him explaining to me while I was just a kid that he evacuated the systems to remove the air and that air contained moisture. He explained that if there was air in the system then there wasn't enough room for the freon and that if there was moisture in the system, it would combine with the freon to make an acid.

I might buy into the possibility of this being an old wives tale, except I've seen the results of systems that have been improperly serviced(not evacuated) that had pinholes in components, evaporators in particular. These days there are more and more aluminum components in systems so I'm not interested in doing anything less than good filter driers and thorough evacuation.

Have a great day,

Hmmm. So in a properly evacuated R-12 system, you have no problems. Moisture will vacuum out of a mineral-oil based system. PAG/POE oils react with the moisture, and once the oil is contaminated, the moisture can NOT be vacuumed out! Sounds to me like R-12 used in a dry system is still fine.

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Larry

I'm sorry that I said some of the things I said. Personally I have to have things proven to me also, that is why I put hydrocarbons into my own system before I ever considered selling it to my customers that I had been doing business with for 15 years.

Hopefully my apologies will be accepted.

gsxr

Yes, R12 always has worked and always will. The problem is most of your average people cannot afford it today. A/C believe it or not is still a luxury, but if you can help people who are struggling just to get by, why not.

redfox,

There are no apologies necessary. We just kick things around here and it's still a free country so we can do and think pretty much what we want to as long as it's legal, ethical and moral.

I sometimes get caught up in discussions such as this, but I mostly just like to talk about MB's and help others with their problems in those rare cases where I'm capable of doing so.

I have no axe to grind with the makers or sellers of Duracool or anything else even though I get carried away with terms sometimes. I have my preferences and everyone else has theirs.

Have a great day,

gsxr

Water boils at -90 degrees in a perfect vacuum which we cannot obtain with conventional equipment. If someone is vacuuming down your system I would recommend at least 28 in. for 1 hour.

gsxr,

Now that you have me thinking here, I think it is the POE or PAG that cause the 134 system to be worse about creating acid when not properly evacuated. The moisture that might be trapped in these synthetic oils eventually makes its way into combination with the refrigerant. I'm not sure if this is the case or not, but I am convinced that the moisture combining with refrigerant to create an acid problem is worse in a 134 system than in a 12 system.

In the past I have gotten about as carried away with a/c system evacuation as I do with oil changes. I find myself going to all lengths to get it as dry as possible. I have probably replaced some driers that really didn't need replacing. This is all because of my obsessiveness.

Have a great day,

Gsxr, while I am no " website" I did photo several paragraphs in my Auto AC book.... 1982 version .. so nothing about 134a...

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Good stuff - thanks!!

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I'm rebuilding an A/C off a car that has sat several years. A local shop is rebuilding the A/C hoses and I was going to use R134A with a new compressor/accumulator/condensor, 134 expansion valve and ester oil. If I choose to use 12A which oil is best and do I need to go back to an R12 expansion valve? And how much oil goes in the compressor and how much in the rest of the system? I evacuate the system down to 0.02 in hg (measured on a Heise 12 inch diameter gauge) for 4 hours to remove moisture and check for leaks. Does this sound adequate? No brow beating please.

You may want to call Don Freeman for specific details at Duracool USA regarding Duracool 12a. 800.427.4510. Only used 1- 6oz can of Duracool to bring my system up to cold. (' '
This Kit includes three 6 oz cans and each 6oz is equivalent to 15oz can of 134a and instructions to do it yourself!
Don at Duracool owns a number of Mercedes Benz including the "83 300DT he purchased the day I talked with him. He is friendly, (that's diesel mercedes knowledgeable and friendly)(' ')and willing to give information and talk with you.
The tune up kit includes three cans of Duracool and a charge kit is $39.95 +7.50 SH/H.':
Check his Duracool site. http://www.duracoolusa.com/
I am planning on using the extra cans to convert my 134a systems on my other vehicles to duracool 12a. My Chevy diesel van does not cool very well at all with 134a.
Redfox on this site looks to be a willing source also since he was directly involved in this thread. My first contact was Don

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