OK, this project is all done. Thanks so much for all the help. I replaced the condenser and the accumulator. I added an extra ounce of oil. The hoses all looked really good. I put in the factory charge of 48oz. My old pressure switch had failed in the closed position just as predicted. I checked it ...

Thanks so much for all the help. Here is the chart showing the capacities for the Yukon from my AlldataDiy account. This system does have the rear AC. I’ll probably just drain the oil from the condenser and the accumulator and follow the chart on how much oil to add to the new parts. Hopefully the w...

I understand about the oil loss. Of course, I can't estimate how much was lost. The parts have started to arrive including the pressure switch. I ordered 16oz of PAG 46 oil just in case. I will have to add just a few few ounces of oil to the new condenser and the new accumulator per the service manu...

Just so I really understand how this system works, let me ask a question about the low pressure switch. In normal operation with a fully charged system, does the low pressure switch cycle the compressor on and off. Assuming this is the case, it would certainly explain the freezing issue. As you have...

I see the comment about the low side switch. That is a very good point. It was certainly running at 5 psi so something is wrong with the low pressure sensor or wiring. I'm going to replace the receiver drier anyway so I'll replace the switch while I'm in there. Once the leak is fixed and the low sid...

Ok, that did not take long. I figured out how to remove the grill after watching a YouTube video. I have located the area of the leak. I can reliably detect refrigerant from the condenser on the driver’s side. I also detected a little from the upper fitting on the passenger side (which I believe is ...

OK, thanks. I have tried to detect the leak before but found absolutely nothing. I'll try again. As for weighing the charge, I could theoretically do this but my tools are not ideal for weighing small amounts of refrigerant. First things first, I'll see if I can locate the leak.

OK, here is an update. It was a beautiful day today, maybe 75 degrees. I just set the AC for full auto and 65 degrees. It was running both the front and rear AC (since that is what it does when you hit the auto button). I drove the truck for about 45 minutes. It took that long but it finally froze. ...

I agree, I'm expecting the two issues are not related. The truck will hold a decent charge for several months. I do need to find that leak. But it starts freezing right away after I vacuum the system down and weigh in the factory charge (48 oz). I'm expecting the suction pressure to be low when the ...

OK, I’ll get some pressures while it’s acting up. Today I replaced the oil pressure sending unit so the intake manifold came off. That was not so fun. It’s done so tomorrow I’ll go for a drive and make it freeze. I bought the truck used two years ago. The AC was never quite right. I’ll break out the...