View Full Version : Old A/C systems (Pre 134-a)

05-18-09, 11:07 AM
Has anyone here had to repair or replace their old AC system that was originally R-12?

Which refrigerant did you use and why? If you went to r 134-a what is the performance like and what year is your car?

I replaced my compressor, EVIR, and desicant bag last year. I pulled a vacuum on the system and held it for about an hour, without any noticable loss. Charged it up with R-12 and it was cooling. But then I went into winter and didn't use it.

Well just before spring this year I had a chance to use it and guess what...it didn't cool. I checked under the hood and the compresor wasn't running and got to looking around and noticed bubbles around the return hose where it is crimped at the factory.

Well I can get a new hose manufactured, but due to the cost of the refrigerant, I am debating wheather to get the r-12 again, or try freeze 12 this time, or convert to 134-a. The 134-a really doesn't appeal to me based on all I have heard from other users. I have heard that it just won't cool these big "old" cars.

Any thoughts or comparisons?

05-18-09, 12:07 PM
Use Freeze 12. R134 won't cool as well in a R12 system. I converted both my 92 Roadmaster, and my mother's 84 Fleetwood, and wish I hadn't. If you shop around, you can still find places that have R12. However, it will likely leak out in a car that doesn't see year-round use. This is why I suggest Freeze 12. Also, you can buy it and do it yourself.

05-18-09, 01:04 PM
Both my 77 and 69 were redone using R12, for both performance and authenticity reasons. R134 is going away soon, too, or so I've heard. Whatever you do, don't put R134 in an R12 system. They're incompatible.

Highway Star
05-18-09, 02:08 PM
There's a low pressure switch on the compressor that will shut it down if freon gets too low (around 25lbs?). Sounds like you've lost quite a bit through that hose. I think there's 3 3/4 lbs used in that system, with a little over 10 ozs of oil. That could get rather pricey at cost of R-12 today, if you can even get your hands on some. Might be a good time to convert to something else (once you get the leak fixed).

My '79 has been a little low, and I added 12-14 ozs of R-12 recently, and it's quite cold now (added 2 oz oil). The A-6 compressors may lose a little around the seals over time (oil streak on hood pad?).

As to R-134. I had three vehicles converted. One I still have ('92 Chevy truck). At first it seemed to cool a little less than R-12. But after a few years in use, it actually cools quite good now.

05-18-09, 10:53 PM
Both my 1991 & 1992 Brougham D'Elegances have been converted to R-134 and it cools the cars down just fine.

05-19-09, 04:20 PM
I put R134 in my 1976 brougham in November, its been used extensively since with no problems (at the risk of speaking too soon) Didn't require any different hoses etc I did have to replace the VIR due to it being worn out. It does cool suffuiciently but not as well as R12, another compromise people make to appease the eco-fascists I guess.

05-19-09, 10:59 PM
I agree with Jay, definitely do the Freeze12 thing. I used it in my Fleetwood before the clutch seized on me (its the original). My Brougham was converted to 134 before I got it and it is not nearly as cold as the R-12 systems I have felt recently. My aunt has a '93 F-150 and the AC is amazing and it is still R-12.

Converting to 134 is also an expensive process because you also have to flush the system and change the oil. A gallon of flush is like $70 and you have to take the entire system apart to do it. The Freeze12 can just be charged into the system with no changes at all. You seem very educated about AC stuff but as a reminder, for the love of God stay away from any sealants.

05-20-09, 11:29 AM
I am only educated by what i have read. Thanks for the warning becuase I was wondering how many problems it would create by solving one. What about leak detectors that you actually put in like refrigerant; are they any good, do they cause problems?

05-20-09, 12:05 PM
The simplest and cheapest leak detector is a dye that is placed in with the oil. At night you turn on the car and its AC and wear a special pair of glasses and use a black light to find the leaks. The dye glows under the black light and you just follow it to the leak source.

05-20-09, 05:01 PM
You could also get an electronic leak detector. (http://www.google.com/products?q=AC+refrigerant+leak+tester&hl=en) They're a little pricey, but you should be able to sell it at profit when you're done with it.

I've read about "Freeze 12" and it looks like a suitable replacement and would defiantly be cheaper than recharging with R-12 or converting to run R-134A. Europe plans to ban the use of R-134A by 2011, so it's going the way of R-12.

05-20-09, 10:19 PM
never heard of freeze 12, where can i get some, local autozone or pep boys?

05-21-09, 02:20 AM
What is Europe gonna use instead of R-134???

05-24-09, 04:43 AM
What is Europe gonna use instead of R-134???

I don't know about Europe but down south in new zealand and I believe Australia it looks like iso butane is the leadig contender until some other chemical or combination/ratio of chemicals is found to improve it .There are heaps --maybe 15 chemicals currently approved other than freon and 134a . It appears that iso butane leads the race and is being used quite widely world wide --how good ? don`t know . I understand that all these different refrigerants require colour coding and such things as l/h or r/h thread fittings and /or smaller/larger fittings to ensure the different refrigerants are not mixed.

05-25-09, 08:11 PM
I would stick with R-12, especially since your system is EEVIR and I know of know way to adjust the POA capsule for the different P/T relationship between R-12 and R-134a. R-134a can be made to work, but typically you need a lot more condenser and fan capacity, oil change, and R-134a compatible desiccant in the EEVIR. You'd also want to change out the ceramic shaft seal on the A6 and replace it with the newer double lip version (and AC/Delco part).

You can leak test with R-134a before using the expense stuff (R-12)... charge up, add dye, and poke the electronic detector around, but do NOT run the system with just R-134a... the oils are incompatible and that A6 will seize up.

Do NOT use any sealers or conditioners.

What a bunch of BS... all in the name this misguided idiocy that your air conditioner blew a hole in the ozone layer. As Adolph Hitler said in Mein Kampf, "The great mass of people will more easily fall victim to a big lie than to a small one." And judging by how many people have bought into the global warming BS, those words are prophetic.