MG leaking fuel only when full?

[Andy]

Been an eventful start of the year again for the turbo. After having to replace the fuel pump a few weeks ago that had just been replaced before it went into hibernation last year the tank that had last year just been replaced leaks when full. Thought it stank and used a lot of petrol the first time I took it out a few weeks ago on a 40 mile run but when I stopped the smell had gone and there was no leak. Just filled it up again and come home and its trailing a solid line of petrol behind it! Not been leaking while running about town the last few days at under half tank. Could be this the fuel sender again? Hope its reparable as that used tank took me an age to find. Cant see me finding another one.

[Jeff Turbo]

Have a look at the fuel filler pipe and associated pipes to the tank. Fuel filler breather pipe can leak

[Andy]

Presume the tank will have to be removed to check these? I take it that in the meantime it will be safe to drive ones its finished spilling out ha, long as I don't fill it right up again?

[Jez]

ok, Various options, should be easy to pinpoint.

1] Leak from the seam in the fuel tank, should start to show itself with more than 3-4 gallons in the tank. removal of tank and repair required.

2] Leak from the fuel level sensor on the tank. Should start to show itself with more than 3-4 gallons in the tank. The metal ring and rubber seal are standard classic mini parts. however the tabs on the tank that hold the ring can rust away making repair harder. You can change the ring and seal with the tank in situ.

3] The fuel filler pipe can be rusted, which can leave holes in the main pipe or the breather. This could be the most likley if only happening when really full.

4] general hole in the fuel tank high up, only showing itself when really full.

I have sufferd from all of these in the past!