Marlon

I read somewhere on a 'search' post about 993 a/c and it mentioned that the 993 a/c psi is actually supposed to be rather low - as in 15 or so???

briefescape

Thanks Mark for info and link .
After following DIY I now believe my problem is a vacuum leak
Everything else seems to work like it ought to .
Cheers Guy

Bgoldey

FWIW-
Just paid $144, for evacuate, charge, press check low/high, dye leak check and refrigerant. Dealer wanted $350.

Brian

Don Magee

Went and looked at my early build 95, and I see the plastic cap for the low pressure side, but about two inches below it I see another plastic cap that has an "L" on it. Which do you use to add the new freon? From the photos above, it looks like the top cap, correct?

Daniel993

Hi, got a tip from one of the Porsche Engineers who recommended
never to turn off the AIRCO , just adapt the temperature in the car when needed.
Will often avoid a leak problems.
Daniel

Quadcammer

just like to point out that the refrigerant with the stop-leak is a horrible idea. It will literally gum up your entire A/C system, and thats one repair you don't want to see ($$$$). If you have a leak, get it fixed properly, or live with it if its really small. From what I understand, all automotive a/c systems leak an absolutely miniscule amount, even when new.

Don Magee

Paging Dr. Cabrio993...
I hooked up th pressure tester to the low side port, and according to the gauge, it was about 40psi? WTF? Now, it was tight at 100 degrees F.(Texas) and I had both "snowflake" buttons in, and the recir. button in. How can this be? FYI, my symptom or problem is that the AC works ok on short trips, but blows only slightly cool are on trips over 1 hour. Thoughts? If this should be a seperate thread, let me know and I'll move it. Thanks.

cabrio993

Thanks for the "Dr." title...but "Mr Hack" would be more appropriate LOL.

If your gauge shows 40psi, it means that you have too much refrigerant in the system. When the psi's are above the amount called for, the system won't cool efficiently just as if didn't have enough refrigerant.

Remember that what makes the refrigerant cold is the delta in gas pressure from the high pressure side, to the low side. So, as the compressed liquid refrigerant is decompressed and turned into gas, it cools rapidly. It passes thorugh the coils where the air is cooled as it runs through it. The compressor compressed the gas again into liquid and is released into the low pressure side repeating the cycle. If you have too much refrigerant in the system, there is not enough room for the liquid to decompress into gas in the system on the low pressure side and therefore not cooling as efficiently.

That's my simplistic understanding of AC systems.

So, you can remove or flush some refrigerant from the system by hooking up the gague and using the valve to let some refrigerant out until it reaches about 17psi (assuming 90+ ambient temperature). This should make your AC work again. The reason that in your case it doesn't cool enough on long trips is because you are moving more volume of air thru the not so cold coils. When you are standing still, the not so cold coils are good enough to cool the smaller volumes of air.

I hope this helps...

Signed..."Mr. Hack"