[GWN7]

Just had mine topped up last week. Supposed to be 1.5 lbs of coolant in the system and there was only 1/2 lbs. They evacuee the system, tested with nitrogen and refilled to 1.5 lbs. and added a dye to see if any leaks develop. Cost $190

The tec told me this is common on GM vehicles. The compressor seal will leak when the weather gets cold. I'm talking -35 ish. New rebuilt compressor is $600 and it might last a couple years or top up when it stops blowing cold every couple years.

Take it to a shop and they can figure out what is wrong.