Retrofitting an R-12 auto A/C system to R-134a

[dud]

The A/C in my '93 is starting to blow warm and I want to recharge it ... but alas it uses R-12 refrigerant, a nearly impossible thing to get these days. I have two options:

1- use a replacement refrigerant like this: Freeze 12

or

2- Retrofit my system to use R-134a. This will involve evacuating the system, using new lubricating oil and refrigerant.


My question is has anyone here done either of these with an old R-12 system ... or if not what other alternatives do I have?

 

[thedarkwolf]

I'm running one of the freeze12 type things in my van and have been for 6 years now. Still works great. I did the conversion on my mustang because I wanted it done right and it doesn't work as well. Two different cars though so the mustang may well have sucked with r-12 too.

 

[Zenmervolt]

R-134a is less efficient and while it is possible to simply evacuate and replace the receiver/drier and the oil, you will have less cooling capacity than you did with R-12. To gain back the cooling capacity you will need a larger compressor and a larger condenser. Even then R-134a runs higher pressures and does not carry oil quite as well.

Overall, I recommend Duracool. http://www.duracool.com/

I have used it in my own cars for several years and it performs wonderfully.

ZV

 

[kalrith]

Originally posted by: Zenmervolt
R-134a is less efficient and while it is possible to simply evacuate and replace the receiver/drier and the oil, you will have less cooling capacity than you did with R-12. To gain back the cooling capacity you will need a larger compressor and a larger condenser. Even then R-134a runs higher pressures and does not carry oil quite as well.

Overall, I recommend Duracool. http://www.duracool.com/

I have used it in my own cars for several years and it performs wonderfully.

ZV

How many of their 6-oz cans would it take to fill up an R-12 system? My car's a '92 Mercury Cougar and is pretty much out of refrigerant.

 

[Iron Woode]

Originally posted by: dud

The A/C in my '93 is starting to blow warm and I want to recharge it ... but alas it uses R-12 refrigerant, a nearly impossible thing to get these days. I have two options:

1- use a replacement refrigerant like this: Freeze 12

or

2- Retrofit my system to use R-134a. This will involve evacuating the system, using new lubricating oil and refrigerant.


My question is has anyone here done either of these with an old R-12 system ... or if not what other alternatives do I have?

I have retro-fitted my 1987 Crown Vic.

I needed a new accumulator/dryer, fixed orifice tube, fittings and proper oil. I also replaced all the O-rings with green neoprene ones designed for R-134a.

Works great and just as cold as the old R-12 stuff was.

 

[bruceb]

The Duracool web site, says that after all the R-12 is out and the system evacuated
that you use 35% charge of Duralcoo 12 of the original amount of R-12 per the
cars underhood label. Below is from the duracool site:

To replace CFC-12 with DURACOOL 12a® requires the removal of all existing refrigerant. Charge the DURACOOL 12a® using 35% of the original (CFC-12) charge weight listed on the system tag. eg; system tag calls for 40oz of CFC-12, use 14oz DURACOOL 12a®. Since DURACOOL 12a® is compatible with the mineral oils there is no need to change or flush your system. DURACOOL 12a® will work with the existing components. Pull a vacuum to at least -10 in hg. If a vacuum pump is not available be sure to use Duracool® DuraDry? to remove system moisture.

http://www.duracool.com/Duracool/faqs.html