W202 Fuel Leak

[poitin]

I have a 1996 C220. When I top off the fuel tank, gasoline leaks from the right rear, dripping off of the fill tube. Once I drive ~20 miles, the leak ceases. Would anyone have some educated suggestions on the likely source/location of the leak? Also, would anyone have a diagram of the fuel tank? Thanks for any hints or suggestions.

[Ethan]

are you letting the gas pump shut off under it's own sensor or are you flicking the handle trigger till gas rises to the entrance of the filler tube?

I had read in another post, some time in the past, how a filler neck tube had misaligned causing a leak - think it was a 202 C class.

[poitin]

I have been topping it off.

I found a thread elsewhere describing similar symptoms. In this case it was the fuel tank vent hose. I'm going to look at it in depth this weekend.
Does anyone knowhow hard is it to replace the hose? Can I access it without dropping the tank? Thanks.

[Benzadmiral]

That happened to me about two weeks ago on my W202.

Normally I fill until the pump clicks off. Nowadays, though, a lot of the el cheapo pumps (not only at off-brand stations, either!) don't have the little steps for the trigger to sit against, or they click off *way* too soon, so you have to pump manually. I filled and filled, and it never clicked off. Suddenly I heard and saw gas bubbling out around the filler neck.

I stopped right away, but when I came back from paying, gas had spilled out onto the ground. It continued to leak, scaring the hell out of me, until I left the car parked at home for about 20 minutes, and then it stopped. As far as I was able to research it here, it's a safety feature. After all, if you try to force 16 gal. into a tank that holds 15, the excess has to go somewhere.

Now if this happens every time you gas up, even after the handle clicks off, that's another ballgame.

[poitin]

I got lucky.

It was the vent hose. The original one had cracked and decayed. It was just a matter of taking off the right rear wheel and swapping out the hose.