leaking fuel

[tupacboy]

so my car started to leak fuel on sunday.... on the passenger side, right in front of the back tire (about 10 inches)... my gas tank is on that side... it only leaks when my car is running... so i figured it was the gas line... tried it again on monday... cause mechanics are not open on sunday... and monday it leaks... today i pay $50 bucks to tow it to my mechanic and he says there's no leak... turn on the car... raised it up... ran it around a couple blocks... and nothing... i told him i'm leaving it there overnight cause i have meetings all day tomorrow and don't really need my car... but i can't figure out what happened... anyone have any ideas?

[ufcrusher]

Yep, here is a question. Did you just fill you gas tank before you noticed the leak? Seems like a weird question but I know that some cars will leak gas when the tanks are filled over capacity or close to maximum capacity.

If not, how much driving did you do on Sunday? Did you use up enough gas that it might have lowered below the level where it was leaking? Just my $0.02.

[Bires]

That's probably it. Most cars will leak out of their check valves. This is why you should NEVER top your gas tank off.

Remember, gasoline is a mixture of volatile liquids, which can increase in volume up to 5% with normal temperature changes.

Gas stored in a colder tank in the ground can expand when put in a hot car, but it takes some time.

[tupacboy]

i drove 60 miles... so i dunno... is that enough driving?

[AlpineJay]

Assuming your car gets 20-25mpg, 60 miles would have consumed a couple gallons. I'd have to believe that was enough to un-top off the fuel in the tank?