Brothers of The Benz
Steve, my memory isn't as sharp as it used to be and your chart will confirm your figures. Your correct, I left the decimal point off of the 1 micron Torr, it is 0.10 micron Torr.
What You and I are saying is you must maintain a condition of low pressure to dry the system. Whether it is 29"hg or 0.10 micron.
Jim, 52*F discharge air Temp is quite good depending on the ambient temperature. If it is 85*F ambient you have a drop of 33*F or 38% cooling. That's good. And this isn't considerring the humidity.
In discussing the various methods we all have performed or seen done shows how forgiving the automotive airconditioner is. The better we apply our knowledge the better the A/C performs.
The automotive A/C is a far cry from a sub-zero type where using a different refrigirant requires the driest of system.
This brings to mind the first units I worked on. It was on Chrysler Automobiles and they used R-22 in a Servel trunk unit. The discharge temp at the nozzles on the rear package shelf was 45-50*F.
There is an additive that can be added to the R134A to improve on the coolig. It is "Performance Booster" Additive. It improves the cooling by 8%. It's a 3 oz can and cost me $10.45.
Possibly by the fumbling of an over the hill mechanic and the help of Steve your A/C will perform up to your expectations.
Happy Trails Beep Beep from The Spiderman in Houston!!!