1999 GMC Jimmy a/c pressure problem?

[Marcos1]

When we got the car the system was empty, we put 18oz of r-134a into it and it started working again and held a pressure of 35 on the low side port. This season I put more in because the system takes 1lb 18oz, I put a 22oz can in when it was 85 degrees out and the pressure wouldn't go any higher than 40. I went through the whole can with no change, it should be at 50 psi. What's wrong?

 

[Humveetech]

Before you added the refrigerant, did you evacuate the system by pulling a vacuum on it for at least 30 minutes??? If you didnt, most likely the compressor is gone, the receiver/dryer is shot too. If you get too much moisture in the system, it can destroy the desccisant bag.

You dont want that much pressure on the low side I am assuming, First off, you added 1lb 2oz, then you added another 1lb 6oz. Your vehicle takes 2lbs even. I suggest you take it somewhere that has a machine & let them remove it all & pull a vacuum on the system & then add the correct amount & then go from there.

Not sure why people got to add more & more, over charging is as bad as undercharged. The first thing I do when people bring their vehicles into our dealership is I have to remove it all & start from the beginning. Since I have seen people add as much as 3 lbs in a 2lb system. Need to exactly how much is in the vehicle instead of guessing. We also add leak dye so if there are any leaks, you will know it