got the Aquatica 5D III, installed that Airlock and well it's leaking after pumping it to -5 after 5min I have -3 then 15min later nothing. I tried listening where the pressure leakes but nothing.
Strange, I can't keep it to hold the -5 for more than 2min.
The soapy water idea will not yield good results. Fill the housing with weights and paper towels. Submerge it in water for a while and open it and look for dampness. If none found reassemble it, connect up the vacuum pump, submerge the housing in water and draw a vacuum on it. If it doesn't hold vacuum it will be sucking in water where the leak is unless you have a leaky input valve.
I hope that helps.