Fuel System Testing

[ka6dan]

Yesterday I made the final installation of my Aux fuel pump. So I now have all the in cockpit tubing installed (tubing from the wing roots thru the fuel selector, aux pump to the firewall). I would like to do some kind of leak test for that section of hardware. Is there a method for in progress testing?

[Dan Langhout]

When I was at this stage, I plumbed some aluminum line with appropriate fittings to connect the wing root fuel lines into a 2 gallon gas can filled with unleaded ethanol-free fuel and another aluminum tube with fittings from the firewall fitting into an empty 2 gallon gas can. Turned the boost pump on and verified that (a) it pumped fuel from either side and (b) there were no leaks (particularly on the pressure side of the pump). I then capped off the firewall fitting and ran the boost pump again to recheck for leaks on the pressure side (might not find any leaks on the suction side of the pump with this test unless they were really bad).

I have an injected engine with the original AFP boost pump set up and its associated set of spaghetti plumbing - so I was really interested in checking for leaks around all those fittings.

FWIW.