I checked the pressure in my AC system on my 1995 E320 with one of those cheap gauges on a can that my friend had for trying to fix his car. My pressure was 30 pounds and that was in the green on the gauge. From searching and reading a number of posts, I know the cheap gauge may not be callibrated, that more pressure isn't always better, and that the appropriate way to charge is to evacuate the system and add a specific amount of 134a. I am still curious, however, about what the operating pressure typically ends up to be with a full charge. I just couldn't find that number in any of the posts.

How many pounds of pressure is a full charge? There must be some rule of thum that the shops use to say your pressure is low and you need to get charged.

My AC is cool, although I have not read the actual temperature of the air coming from the vents. It just seemd that my compressor was coming on more than I remembered and I checked the pressure. Now I want to know if I could just add a bit to make things better.

Thanks for your help

__________________
I just couldn't give up on my 1995 E320.

I think it might be like always going back to that same bad relationship with an ex girlfriend.
You feel you love them too much, or you are just too stupid to know any better.



Flickr slideshow of my 1995 E320
http://www.flickr.com/photos/24145497@N06/sets/72157616572140057/