2015 Yukon AC only works sometimes

[Dustin Ward]

I have a 2015 Yukon that had the air conditioning stop working. It normally blows hot air, but every now and then it will randomly work great. I added some freon yesterday and the compressor kicked on and everything was working good, but as soon as I turned the rear air on high it started blowing warm again and the compressor stopped cycling. I thought maybe it the rear air thing was just a coincidence and it had leaked all the freon out immediately, but now (a day later) I'm driving and it's been working for a few hours now. Any ideas? Thanks in advance guys. 

[Russ Swift]

FYI:  Had a 2005 XL, had leak between front and rear, $1500+ to find leak in rear, $500+ to replace rear compressor, less than $500 to cut off rear A/C, which is what I had done.  If I did want it fixed I would have started with replacing rear compressor.  Suggest having a radiator-A/C shop check it out and suggest options.  Good Luck.  

[renickh]

Sounds like you have leaked out just enough to hit the low pressure shut of for your AC clutch. When you added 134a it gave you enough refrigerant to keep the pressure high enough to run the front ac. When the back was turned on the pressure dropped and the clutch cuts out. I suggest you add some leak detector and find the source of your loss. My guess is upper driver side condenser (can be seen through the grill), or lower passenger side condenser where the lines attach (bracket was later added due to failures), or near the service ports by the passenger side of the engine (bracket added here later due to failures). Lucky you, 2015 still uses R134a which is cheap. Mine is running the new expensive R1234yf. 
 

GM has a warranty extension they call “special coverage” for condenser failures if your Yukon has less than 75k mi and the VIN number is covered. Has to be the leak at the driver side of the condenser.