I've got a 2000 2.8l 30v A4 that I recently replaced my AC compressor on (or rather my dad did it for me). I'm not getting very cold air coming out. I've put about 3 13oz cans of r-134a. According to the gauge on the can, it's at about 42psi of pressure with the compressor running. It seems to max out there. It didn't seem to change much as I emptied the 3rd can. I don't want to overcharge the system. How much coolant should the system hold? Any ideas on what could be wrong? I checked about a week apart, and the pressure seems to stay constant, so I don't think that there is a leak in the system. Any pointers would be appreciated.

 

You didn't mention if you pulled a vacuum on it to remove all moisture and air in the lines before you added the R-134. Thats the first step you need to do.

Good Luck...

 

...I didn't vacuum the system first. Thanks for the tip. Does that mean that I'll lose the r134a I've already put int?

 

Go have a shop do it with the proper equipment. You MUST draw a vacuum and put the proper amount of oil into the system or bye bye compressor #2.