r12 car air-conditioning

[robin r33 gtr]

I go on a few car forums and keep reading people who say the fill there r12 car systems with r134a and works fine. I find this hard to be true.

So if you have a r12 system can you get a drop in replacement or what are your options.

[Karl Hofmann]

R413a (Trade name Isceon 49) works well. You'd be amazed at how long you can run a compressor using R134a before it dies, the refrigerant somtimes drags the oil with it so the compressor gets a little lubrication, add to this the fact that our aircon season is very short so by next year when the compressor dies it will just be one of those things... It was an old car anyway

Not my view by the way...

[Brian_UK]

As Karl says, use R413a as a good, reliable drop in.

[chillin out]

Yes, it will work most times but as I remember, the seals don't like it.

Chillin

[lana]

What is popular is not always right. What is right is not always popular.

[mickandlee]

I know someone in NZ who charged his old reck of a Honda with gas from the barbi cylinder.

Its worked well for the last two summers.

Not realy recommended but dont challange him to a 'burn up'

Mick

[Paul@paulrobert]

RS24 is the gas you want I find that 413 A tends to leak from the shaft seal too quickly, just remember to switch the a/c on for 5 mins every couple of weeks in winter to keep the o rings from drying out.

[The MG Pony]

I've heard some auto makers are seting it to run for a bit when defrosting windows to dehumidify the air, thus the compy cycles during the winter.

If so nifty idea.

[robin r33 gtr]

Thanks for everyones help.

[Karl Hofmann]

Can't see why Rs24 would leak less than R413a since the major component of both are R134a with a sniff of Propane and butane though RS24 does also have a bit of R125 in it too. Shaft seals are probably just kippered. even the newest R12 car is now 14 years old, so it won't be in tip top shape

Many car manufacturers now use clutchless compressors which even when off, will still run at about 3% of its maximum displacement so running the ac in the winter is becoming a thing of the past

[nh3simman]

If you read the advice from DuPont, R134a should never go near a R12 system without major flushing and component changes. The lubricants are supposedly completely incompatible. But from what I see here, people are doing it anyway.

It would be interesting to know the life of these systems
after charging with R134a.

[Karl Hofmann]

The life expectancy of an R12 system running with R134a is pretty short if the car was in the US or SA but since the UK does have a short AC season and it never really gets that hot here, the compressors can last quite a while. Many bodgers just stick a shot of PAG lubricant ontop of the Mineral oil and the compressor gets a bit of lubrication.

Seals and hoses rarely seem to be a problem, though the dessicant in the older driers can suffer from R134a use. Most people with old bangers wont pay for a proper retrofit though I have done retrofits on a couple of quite nice classics and are quite happy as we go in to their fourth season.

[The MG Pony]

Here they just shove propane in, techs gotta be carefull, one guy nearly lost his face due to the lovely sods who do it. Wouldn't be so bad if they wrote what they shoved in it, seems to run fine and lasts a good while.