I'm going through the same battle now.... By progressive testing, I have narrowed it down to being south of the manifold. I have replaced all the washers in the bodies of the quick connects and the orings on the gas posts. I have soap tested the manifold connection, the quick connect connection, the pressure relief and everywhere else I can spray! Very frustrating, but if I close all the manifold valves, leave it for several hours, reopen each of them, the gas starts flowing (you can hear the moaning) into 3 of the kegs. I was going to replace all my gas poppets and then I realized that with the quick connects on the poppet isn't sealing anyway...... Next is to try lubing up all the gas orings and see if that does anything. The regulator holds pressure when tank and manifold is closed and I even submerged the manifold in a bucket of water to check it.