Took the fuel cap off a Cessna and it sounded like a soda bottle, so I tried the shop vac trick
Last Tuesday I was draining the tanks on a 172 in Amarillo and the fuel was coming out in glugs because the cap vent was plugged solid with dirt. Instead of pulling the whole vent apart I put a shop vac hose near the filler neck on blow, low setting, and the fuel ran smooth as a garden hose in about 40 seconds. Has anyone else used air pressure to burp a tank like this, or am I gonna get yelled at by the next guy who owns this plane?