First off if this is in the wrong section I appoligize. Ok I am going nuts I have a couple leaks in my air compressor system in my garage. The compressor has a shutoff befor it goes to the shop. The compressor leaks down about 40 psi overnight. I have pulled apart all the fittings on the tank. I have re-taped them and screwed them back in. All I can think here is that device that reads the pressure and kicks on power and off. Could this possible loose psi? Also the second system has 3-20 gallon tanks the pressure regulator and water traps. This part of the system looses right about 20 psi overnight (I can live with this). And the main system looses about the same 20 psi. All three "zones" can be shut off independently of the rest. I guess what Im looking for is any new ideas to find the leaks. The whole system has about 120' 3/4 copper(main feed tubes), 80' 1/2 copper(down pipes and drain tubes to remove water from tanks in attic), 2 water traps(1 pipe t's into both then they both t back into one pipe. I was having trouble with the one keeping up.), there are about 15 quick connects, and a hose reel, there are 3-20 gallon tanks and a 80 gallon tank(on the compressor). Any Ideas on what could be leaking All of the connects are after the main shutoff. Thanks alot guys