Ac issue not condenser

Toallhisdoom · May 21

18 silverado 5.3l

Blowing hot air. Took to mechanic and cc recharged and dye added. 1.2lbs put in by shop. Drove home 5 minutes. Truck sat for 24hrs. Went to drive it the next day and ac not working. Lasted less than 48hrs. Back to shop and they checked it and it was completely empty. No signs of UV dye anywhere. They are stumped. It works great when they fill it but must have a major leak, but without any visual leaks where do I go next? They said they used a sniffer and couldnt find anything. I assume the only place left for it to be leaking is the evap behind the dash. Is there any way to see inside and identify a leak without pulling the whole dash apart?

Edited May 21 by Toallhisdoom

Snowcamo · May 21

Refrigerant leak detector.

Toallhisdoom · May 21

25 minutes ago, Snowcamo said:

Refrigerant leak detector.

Sorry forgot to say they tried that. No luck.

mikeyk101 · May 22

oops, I need to work on my reading comprehension. Sorry...

Edited May 22 by mikeyk101

davester · May 22

For my '12 3500, pulling out the fan and resistor pack, you can get a partial direct view of one side of the evaporator, and if the uv dye shows up using a camera, you could see that whole side of the evaporator. And you can cut a hole in the hvac housing to look at the other side (for my '12, GM has you cut a hole to replace the a/c evap temp sensor that is inserted in the evaporator core, then you glue in a plug to seal it up again).