A/C Pressures and amounts 4 930's

[Benny771]

HI:
Anyone know the pressures and amounts of freon....
I have looked in a Bentley book i have for a 911 (not a 930) It states.
47oz of R12
Low side 12-30 psi
High side 115-205 psi Both at 25 degrees.
Freon amounts were not listed in my "free down-loadable" 930 shop manual.

Just wondering if this is the same for a 930, 1989.

What "vent" temp should i be getting if all is well? Apparently the P-cars don't cool as well as others. So I would like to know what is good for this car.

On my Vette 42 was pretty good.

[Benny771]

Really?
No one?

[Ronnie's.930]

This is some excellent A/C info that JFairman gave me last year - probably doesn't really pertain to your questions however, as it deals with pressures and temps of a modded unit (including a switch to r134):

A/C Question . . .

[9dreizig]

In all honesty, while we are truly the brightest and the best minds in the auto world here. I'd go to the mear mortals over in the 911 section,, they have a ton of A/C threads over there ;-)

[JFairman]

If you're using R12 it's easy... just add freon if there is already correct oil in the system until the bubbles go away on the sight glass in the reciever dryer.
Thats in the back edge of the left side front left wheel well.

If the system is totally stock and using stock diameter hoses and you're charging R12 from a 30lb bottle sitting on a scale, the weight of the proper R12 charge is on a sticker on the side of the air cleaner housing.

The regrigerant capacity and weight will probably be a little different between a 911 and 930 because the rear condensors are sized and shaped differently.

On a day in the mid eightees the pressures will be around 30 on the low side and 220 or so on the high side but thats a big generalization depending on temperatures.
Just clean the sight glass and watch it while adding freon until the bubbles go way with it running, rear engine lid down so air is drawn over the condensor. Stop immediately when the bubbles disappear.
You're better off and the air will be cooler a little under charged (but not alot) than over charged.

If using R134 the sight glass is useless and you have to go by pressures and temperatures and it changes non linear and quickly.
Someone already posted a link with help on those.

[Benny771]

I'm using a r12 substitute made by Dura-cool. I have been using it for years in other cars and it works well. And its cheap. DuracoolŪ.com 2004 - DuracoolŪ is The Recognized Leader In Hydrocarbon Refrigerant Technology
But now with the large running lines and the glass eye it has thrown in a new variable.
The system is stock, but i would like to know what Vent temperatures others are getting with these cars (just so i know everything is working right).

Thank-you all for your replies.