Seems the smart thing to do is to put some compressed air into the system and spray some soapy water the connections.
Here is a video that shows the procedure I used
https://www.youtube.com/watch?v=J6DSpx1V3Ms
Basically you put a rubber tipped air gun where the yellow vacuum pump hose goes, and pressurize the system, then with a spray bottle of soap and water get to squirting on your joints.
The great thing about air leaks is that you can *hear them!
So I found the leak!
This puppy was hissing air.
Now, no one in their right mind would put a junk yard Low Pressure Cut Off switch on their brand spanking new AC system...would they???
Next up, we put it back on the vacuum pump and see if it holds! Fingers crossed.