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Why does my fuel tank pump seal seap gas?

It appears that my Mazda protege5 is slowly leaking gas from the ring seal that seals the pump module to the top of the gas tank. It only leaks when the car is running, so it seems that the pressure of the pump is causing this. The mystery to me is that this seal should not be under pressure. I could understand if it was one of the fuel lines, but why at this seal?

I am not familar with the access to the fuel pump on the Protege, is there a inspection plate that you have removed that gives you a clear look at the point on the tank that the pump is installed?

What I am getting at is how can you tell the leak is from the pump retainer O’ring and not from any of the other fill or vent hoses?

Has the tank recently been lowered, pump recently replaced?

Any way once access is gained to the top of the tank replacing the O’ring is not so bad.

You could have a broken (cracked) fitting on the pump.

Access is gained by removing the back seat and removing a cover plate. After doing this I ran the car and observed the gas slowly rising in the cup formed by the top of the fuel pump assembly. I have since removed the assembly and I see a slightly worn seal, but not terribly so. I just don’t see how gas would be forced through this seal. I did not see any gas spurting or leaking from the hose fittings… I suppose it could have been leaking under the fittings where I couldn’t see.

Thanks for responding.