Originally Posted by Elshupacabra
So, now I've removed the whole gas system from the kegs and I'm testing it and it's still dropping. I'll set it to 5PSI and it will drop...4...3..2 within a couple of hours. I fixed the faulty barb and sprayed down everything AGAIN and found no leaks.
So, faulty regulator, super secret leak or what? Next steps?
Well, there is definitely still a leak in your setup as evidenced by the dropping pressure.
The first thing you should do is take everything apart and put it back together with some quality thread tape made for high pressure, gas applications. While you can use more permanent methods of sealing the threads/connections (i.e., JB Weld), that will mean that you won't be able to change the configuration if you decide to expand in the future.