Gas leak found but can't fix, help!

[kaiser16]

Hi everyone, I had a gas leak on my 318is and decided to remove the gas tank and replace some hoses, I discovered one leak in the braided hose that leads to the expansion tank so bought a new hose but for the life of me I CAN'T REMOVE the blasted thing, it goes through a metal tube inside the cabin with two small pipes, I tried burning it, removed the two pipes but still it doesn't move, any success stories out there? The other thing is that all the studs and bolts that hold the gas tank to the car broke off and when I drilled them out I had no choice to damage the threads. I think I have to tap them but any other suggestions? The other gas leak came from the hose that goes to the charcoal canister was dumping the content of the expansion tank on the road so I ran new hard lines.

[keflaman]

Take out the bottom section of your back seat and inspect the pipe that the fuel tank overflow line runs through.


The braided cloth covering wicks moisture down into the pipe causing it to rust through.


In the case of my car, the overflow line was completely encapsulated within the pipe and necessitated replacing the pipe and line.
A replacement pipe is available for ~$10USD (Item #8, http://bmwfans.info/parts/catalog/E30/2-doors/USA/318is-M42/LHD/M/1990/july/browse/bodywork/floor_panel_trunk_wheel_housing_rear/), but I recommend cutting one from another car and include the surrounding metal near each end. The rubber hose runs ~$20USD, but I used 1/2" fuel line instead which made for a much easier time threading that and the two plastic lines through the pipe.


I suspect this was the source of gas fumes inside the passenger compartment, but I replaced the fuel tank and all rubber lines due to rust and age. I've driven over 2K headache-free miles since then.

[DesktopDave]

+1 on that...definitely the right way to fix it.  The parking brake has very similar troubles.

As for the mounting studs...I'd be tempted to cut them all off, drill holes where they were (into the car) and use some high strength bolts in their place.  I'm not sure if they're all easily accessible locations, but you'd have nice new metal for the tank mount.  I'd likely seal them later with some RTV to eliminate any possibility of gas or exhaust fumes.

If you can't weld, there are some excellent epoxies on the market as well.   Eastwood makes a great line of panel adhesives.

[kaiser16]

I was just able to remove the hose, got lucky I suppose, I don't have any holes in the pipe so that can't be the source of my ''headaches'' but someone has patched it up before, but now that I got the hose out I'll replace all the hoses, thanks for the help