Olin83

What coolant are people using for AC recharges, 134A, R12?

John_AZ

Probably, and due to availability, R134a.
http://griffiths.com/ac-system-help-.../r134a-vs-r12/

I am satisfied with my '87 R134a conversion but the R12 in the '88 is best.

If you want to get the best cooling, buy the dual tube condenser from Griffiths if you convert to R134a.
http://griffiths.com/product-categor...1985-2-onward/

J_AZ

V2Rocket

Parallel flow unit is very good upgrade

On my early car I am satisfied with the R134a conversion. On the freeway it is necessary to dial the AC down because it gets so cold.

Around town it works well except for on really hot days (90F+)...it still cools you but could be better. But part of that is poor ducting and air flow distribution which shouldn't be hard to remedy. But the evaporator could be larger and the fan have a higher speed setting...

Late 944 AC systems are harder to work on, but they work better at cooling

BeerBurner

I've been very happy with my R134a converted system.

Sometimes I end up turning the heat on a little bit when that happens.

BB.

Arominus

My 134 conversion hates city work, but it does the job. On the highway its great as it can dump more heat with the higher speed airflow. That griffiths upgrade would probably solve the city thing.

R12 is better if you can get it, but it is more expensive. My system was already converted when i bought the car, so i stuck with it. Going back is a giant pain in the ***.

Dash01

Anybody here tried Duracool or other propane derivatives? It reportedly replaces R-12, works better, at a small fraction the cost. Pressure at ~30 lbs. is way lower than R-12 or R-134, so it's said to be easier on the seals

Tim_944

i'm interested in the hydrocarbon replacements also but worried about fire/ explosion hazard.

PaulD_944S2

I'd be more worried about 10-20 gallons of hydrocarbons under the rear deck.

Tim_944

but with the AC you have pressurized gas running behind your dash. if there is a leak you can have the interior fill with propane.

944Ross

Most A/C shops won't even look at any system that has ever had a hydrocarbon-based refrigerant in it. Not seeing the point anyway, I've converted both an early and late car with $20 of fittings and they make my nipples hard in a few minutes.

Tim_944

did you just convert the fittings and then run r134? I heard conversion is costly because you have to replace all the seals which includes ones behind the dash, and then you got to switch the oil in the compressor to one compatible with r134 and I think change over the evaporator and preferable change the compressor to one that can handle higher pressures....

BeerBurner

On my 944, I only had the receiver drier replaced for the conversion (although I did end up putting in a new expansion valve so those got replaced, too). I ended up not even doing that much on my Miata... the system was empty so I just plugged in a conversion kit and have been enjoying cold AC since 2006.

I'll add the warning that the Miata's conversion was done in such a horribly incorrect way that even I have a hard time believing it worked so I either got lucky or the fears about conversions are sometimes overstated. My money is on "luck"...

BB.

harveyf

Exactly answering your question, you need to recharge with whatever is (or was) in there now. You know you can't mix the various refrigerants? If the car has ever been charged with R134 it should have the oversize fittings on the ports. The kind that you pull the collar on the hose fitting back to connect the hose for the recharge can. The R12 fittings are clearly different as they are male threads designed for hoses with female threads and much smaller in diameter, about 3/8" dia.

The system was designed for R12. It will work the best with R12. R12 isn't that expensive. I just did my 928 and used 3 cans at $35 a can from 928RUS. R134 would have been maybe $10 a can. Where it gets expensive is if you have a leak. As others have said, a conversion to R134 will lead to satisfactory performance if done right.

These systems are 25 years old. In a perfect world you would replace all the o-rings ($12 parts, god knows how much if you pay someone else to do it, doable yourself) and the dryer at a minimum. There are a ton of threads on AC on the 944 and 928 sites. Read them.

Arominus

I would replace the dryer no matter what if the system has drawn down. Youll be putting it under vac anyways so might as well do it right.

audi49

Have searched the forums and there seem to be different versions of what to do.

Is the first link above what is needed at minimum? Are only 6 o-rings needed? I thought there were many more.

Also I assume that they recommend having a professional empty the system. Is that to capture the refrigerant? Since mine doesn't cool does that mean that I can do it myself? Or is there some other reason to get a professional involved?

Thank you!