Fuel system pressure test

31 Mar 2006 Fuel system pressure test

To test the fuel system, I hooked up some fittings between the intake and return fuel lines just outside the fuselage. I put a + on there, with the “schrader” valve that comes with the Van’s fuel tank leak test kit:
http://www.vansaircraft.com/cgi-bin/catalog.cgi?browse=misc&product=tank-test

Two standard hose barbs, and a pressure gauge. A bicycle pump is what I used to pressurize the system.

So, this tested the whole system, except the tanks, which I have already tested.

I tested the fuel system plumbing with air pressure, and sprayed
soapy water on the outside to look for bubbles. I found
that almost every single AN connector leaked. Once I
got those fixed, I pressurized the system to about
50-60 psi, and then took periodic measurements over
the next week or so to watch it leak down. It never
got below about 20psi, IIRC, so I claimed victory.