A/C Conversion

[kelevanwinkle]

was there ever a Tech article on doing the RN-134 air conditioning conversion? or did i just completely think up of something else?

[86MarkVIILSC]

I'm pretty sure there isn't.....

[Lee Joffe]

Suck out the R12, recharge with R134a and the correct oil.

[demonswede]

On my 1984 - the former owner swapped the heater core & had the system juste recharged with R 134 (only available gas here) & did nothing more (I have checked with the technichian). Worked perfectly for a couple of years including my long trips on a hot summer after the spring I bought the car.

Late fall I had to swap the heater core again (first time for me - the real right way - second time was the cesarian way) & I recharged with R 12 (which I was able to obtain).

System works perfectly with no leaks.

[Robb]

I switched mine over to freeze12. After doing the research it seemed a much better alternative than 134. You can buy it on ebay and it is made for our older cars.

http://freeze12.net/

[86MarkVIILSC]

I switched mine over to freeze12. After doing the research it seemed a much better alternative than 134. You can buy it on ebay and it is made for our older cars.

http://freeze12.net/
That looks like what I will be doing with my Mark now.....:)

[LSRX101]

was there ever a Tech article on doing the RN-134 air conditioning conversion? or did i just completely think up of something else?

There'a no tech article here on LOL, but if you do a search here: www.autoacforum.com You will find more information than you ever wanted to know about R12-R134a conversion.

On most Ford products, it's a pretty simple procedure. Keep in mind that the newest R12 system is now 14 years old and past due for a full service:

-Evacuate any remaining R-12.
-Replace the accumulator and orifice tube.
-Replace any suspect hoses.
-Thoroughly flush the remaining parts of the system with solvent (lacquer thinner, denatured alcohol, etc) and lots of compressed air to remove the old mineral oil.
-Flush the compressor with the oil you plan to use.
-Reassemble the system replacing all of the hose connection seals.
-Add the recommended amount of BVA Ester or PAG 60 oil to the system.
-Evacuate and recharge to about 80% of the recommended R12 charge with R134a.
-Tweak the system 1oz at a time until the vent temps stop dropping (1500 rpm, MAX AC, doors closed). Allow 5 minutes between 1oz shots for the system to stabilize.

Notice many of these steps (accumlator replacement, flushing, resealing) are the steps necessary to properly service an old AC system regardless of refrigerant. This also verifies the amount of oil in the system. Considering the age of the components you would, hopefully, do all these things even if using R12.

[LSRX101]

I switched mine over to freeze12. After doing the research it seemed a much better alternative than 134. You can buy it on ebay and it is made for our older cars.

http://freeze12.net/

Umm, yeaaa, About that Freeze12 stuff,
Freeze-12 is 80% R134a with R142b added to carry the old R12 mineral oil through the system. The R134a does the cooling and the R142 carries the oil. How can it be "better"? It is chemically the same as R134a as far as the temperature/pressure curve is concerned.
Freeze12 works very well as a refrigerant in automobile AC systems but it simply cannot work "better" than R134a, because it IS R134a.

You bought snake oil, my friend. People get taken by the excellent marketing of Freeze-12 every day, so you aren't alone. That Freeze12.net site is very convincing. If you look close and think about what you are reading though, there are only 2 things that say anything useful, and they're both untrue.

TCCs claims about "cooling better than R12" and having a "lower pressure curve" than R134a are totally false. This has been proven uncounted times since the information on that site was written (1994). There was some juggling of numbers used to get Johnsons pressure curve specs and they were slapped on the hand for it long ago. (Part of the reason that it is now marketed by TCC).

One thing that they fail to mention in all of the praise is that fact that FR12 is a "blended" refrigerant. The 2 gases separate when the system is idle. If you have a small leak, guess which one will leak out first? The R142, the gas that carries the oil to your compressor!
If you "top off" the system you now have too much R134a in the system and not enough R142b to reliably carry the oil back to the compressor. Guess what happens when you starve the compressor for oil?? This is why parts manufacturers (still) will not warranty parts used with Freeze 12.

The only "advantage" to Freeze12 over R134a is that it will carry mineral oil with R134a. This was great when these systems were only a few years old. You could fix a leak, evacuate, recharge with FR12 and the system would work a while longer. (not "quite" as well as with R12).
Now that the newest R12 system is 14 years old, do you really want 14 year old oil in your system and R134a running through that old desiccant bag in the accumulator, all held in with 14 year old rubber o-rings? Well, you might get lucky for a little while. Probably not.

Today, Freeze 12 is a good solution, looking for a niche to fill. That niche closed up when R12 systems got to be 8-10 years old and required more than a simple leak fix and recharge to keep them cooling reliably. TCC has found another niche, though, and they use sleazy practices to sell their product.
They market FR12 to people who don't know how to properly service an AC system. They will tell you why you should use it in an older car and make it very attractive to do so, but if your compressor fails because the 15+ year old desiccant bag in the accumulator ruptured, or because you "topped off" instead of fixing a leak and totally recharging, too bad for you.
TCC certainly can't be held responsible because YOU didn't practice "industry recommended' proper repair procedures on an "old" car, right?
Oh, your new or "reman" compressor failed and the parts store won't warranty it? It must have been defective. Anyway, we never said that our product was accepted for parts warranty. YOU probably didn't ask when you bought it, did you? (due diligence). We only claim that our product is accepted by the EPA for use in MVAC. (It won't harm the environment).

Freeze 12 was once a semi-respectable product that filled a need. Now, it's just overhyped snake oil that does more harm than good.

My apologies for the long rant, I just feel very strongly about this subject.
I do MVAC repair as a side business and see the outcome when products like this don't work. TCC and Interdynamics bring me lots of customers after their "quick fixes and miracle cures" fail.
I love to make money doing MVAC repair, just not on the backs of people who thought they couldn't afford a "proper AC repair" in the first place and now have to pay much more due to shady marketing by these companies.

[kelevanwinkle]

haha wow, got alot of feedback, i guess the "N" wasnt apart of it. I'm about to get a daily driver car and use my MK7 as like a street/track car, so maybe i wont even use my AC anymore (not that i use it now anyways). thanks!!

[pro-five-oh]

I have R134 in mine, and I'm not happy with it. It doesn't cool as well in the really hot afternoons here in Houston when there's not much circulation in traffic. Its just not as efficient as R12.

A friend has a '70s Porsche 911 that was converted to R134, than went to freeze 12. He says the Freeze stuff is just as good as R12, and its probably true because 911's a/c system isn't nearly as robust as a Mark VIIs.

I'd recommend Freeze 12 just for that reason.

[LSRX101]

haha wow, got alot of feedback, i guess the "N" wasnt apart of it. I'm about to get a daily driver car and use my MK7 as like a street/track car, so maybe i wont even use my AC anymore (not that i use it now anyways). thanks!!

What is the daily driver car?
The system might not "explode" immediately if you do a less than correct R134a conversion. If you only plan to keep the car a year or so, I can tell you how to do it with no guarantee of longevity. It might work for 1 month, or go until you sell the car and beyond. It's a real crapshoot. It depends on the model.

You mention the "N". as being not part of the replies. You mentioned RN-134 earlier and I took that as a typo.
R stands for refrigerant. Refrigerant chemicals are always listed as R-(something), as in R-12, R-134a,- 142b, etc.
If you see a product listed as RX-something, think twice then walk away.

[LSRX101]

I have R134 in mine, and I'm not happy with it. It doesn't cool as well in the really hot afternoons here in Houston when there's not much circulation in traffic. Its just not as efficient as R12.

A friend has a '70s Porsche 911 that was converted to R134, than went to freeze 12. He says the Freeze stuff is just as good as R12, and its probably true because 911's a/c system isn't nearly as robust as a Mark VIIs.

I'd recommend Freeze 12 just for that reason.


Sorry Pro. If your car doesn't do well with R134a,(done properly) it will perform just as bad with Freeze 12. Your condenser was designed for R12 . To get the best results with R134a (or FR-12) you need more air flow over the condenser or a more efficient condenser.
There is NO way that Porsche cools "better" with FR12 than R134a. It's the same gosh darn refrigerant!! Period!. There's either some placebo effect going on or the system prep was very different for both refrigerants. From what I've heard, most Porsche R-12 AC systems were plagued with condenser airflow issues to start with, so I have to call total BS on any FR-12/R134a conversion working "good"on that car.

[Bluegrass]

LSRX is correct.
134 requires a larger condenser and at min more airflow through an R12 unit to be near corrrect with 134.
A system changeover needs a new larger condenser along with the rest of the parts to be correct over the long term.
An R12 system just refilled with 134 most often never gets the outlet temps down low enough for proper cooling in very hot climates and slow traffic speeds when the condenser is too small to complete the refrig cycle within the system.
Also, in an old leaky 12 system, the 134 will leak out even faster.

[joeythefixer]

I did the R134 conversion a couple of years ago, pretty painless. It works well most of the time but not as good as the R12.

[LSRX101]

I did the R134 conversion a couple of years ago, pretty painless. It works well most of the time but not as good as the R12.
Did you do the Interdynamics Conversion kit retrofit, or did you do it the "right" way? There's a big difference.

[joeythefixer]

I completely flushed out the system, changed all the O rings, dryer, and expansion tube. Evacuated the system, added the correct oil and 134.
when the compressor gives up (still the original) I'll replace it with one designed for 134.
I've had more problems with the clutch. everyone tries to sell me the wrong one. I ended up going to the junk yard and pulling 3 that had some life left in em. so far so good!

[Taurus90]

R12, R134a, freeze12 ... Very confusing!
Some weeks ago I let someone filling up the A/C with R413a (1000g) - but some days later the whole thing was on the floor. So I'm thinking of change some parts of the A/C to converse to the new/legally refrigant (is it R12 or R134?) - but really don't know what I've to change? Are the new compressors designed for the new refrigant? And the accumulators? And and and.
I have not the money for a repair shop to to it for me, so I need info ...