Fuel Filter Hoses LEAK

[c0rbin9]

Last weekend I replaced the fuel filter in my 318is, this weekend I start the car and drive it around the block in preparation for draining the coolant, and find out that I've got fuel dumping out of the fuel filter area.

The gas seems to be coming from the hose that connects from the fuel filter to the tank, the one closest to the rear of the car. I'm ready to change it, but I don't see where it connects on the gas tank side. Also I currently have a stripped interior and could tell that fuel was pooling/backing up outside the fuel pump and on top of the tank itself. Any ideas?

[oldmann]

Under back seat, passenger side, pull the fuel pump cover. All the hoses are there.

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[c0rbin9]

Thanks.

Anyone know where to buy the o-ring that seals the fuel pump housing to the tank? Can't find it on Pelican Parts.

[Boris3]

In my case it was the high pressure hard line that runs across the top of the tank. These can rust through and leaking fuel will run along the top of the tank: both pooling on top of the pump and running down the driver's side resembling a leak in the hose to the fuel filter.

[c0rbin9]

I'll have to look into that, as those are my symptoms exactly.

[Boris3]

More common problem up here in rust belt than down by you in Texas.

One way to tell is to pull the access covers under the rear seat, clean up any pooled fuel on top of the pump housing to make sure everything is dry, and then start the car. If the hard line is rusted through, look through the passenger side access panel and you'll see a stream of fuel running towards the fuel pump. Depending on the surface where you're parked, look through the access panel on the driver's side and you'll see fuel running between the hard line and the rubber fuel return line towards the driver's side of the car.

To really make sure either drop/replace the tank, or bypass the hard line by running BWM high pressure rubber fuel line (8x13mm, you'll need between 5-6 feet) from the pump to the fuel filter (thread the hose alongside the hardline on the top of the tank, use the driver's side access plate and feed one end towards the pump and the other towards the filter--plug the ends so you don't get any crap from the top of the tank in the hose). If everything is dry once you run the car for a while you've found your problem.

[c0rbin9]

I replaced 3 hoses on the passenger side of the tank (long return line, fuel filter in, fuel filter out) last weekend and presto, no more leaking. I actually bypassed the hardline with a proper pressure long hose for the fuel filter-in line, as I think that was where the leak was and I wasn't prepared to drop/replace the tank. Thanks for the tip, Boris!

There is still a moderate smell of gas in the cabin. Also still have the 2 fuel tank access covers removed as I don't think the car came with the larger one that covers the pump - maybe that is why there is still a smell? Next I'm going to replace the fuel pump gasket as that area seems to have the most smell. After that the only other possibilities are the big braided vent hose and the tank itself.

Also have a problem where the car cuts power in left handed corners - fuel pump?