I've only owned this car for a couple of days and only filled the gas tank up twice. Once to check it for the leak and yesterday when the leak actually occurred. But sure as crap, it happened. Pulled into my garage after filling up and had a strong raw fuel smell. Actually saw a small puddle of fuel. Pulled my backseat and saw this.



Now in this particular case, the car had already had the supposed "fuel pump recall" performed on it. I actually spoke with the dealer that did the work and they had worked on the driver's side pump on March of 2012. Even has the sticker under the hood. Yet here was the leak, and bad too. My fear was that maybe it was the fuel tank. Yet in speaking to a couple of my friends, they were pretty adamant it was the gasket. Decided "what the hell" and began my $25 experiment/fact finding diagnosis.

Tools and materials required:
New gasket
fuel hose clamp (of your choice)
dikes
ratchet with 8mm socket
large flathead screwdriver
hammer
Optional:
pliers

The whole gasket swap took 45 minutes with me muddling through this. It also cost me about a half gallon of lost fuel. I highly recommend you do this with under 3/4 of a tank of gas if possible. As bad as my leak was, I did not have that option.
Please note that to swap the gasket you do not have to completely remove the fuel pump assembly. Once you remove the fuel hose and plugs, the gasket can be removed and re-installed over the top. On re-installation, pay very close attention to the gasket as it does not simply slide into the fuel tank. Slowly and carefully work it into the tank on the pump housing with only your fingers. It will go in.

So here's the problem gasket. My diagnosis: inferior material with signs of potential bad installation. The old gasket was quite a bit softer than the new one. I've seen this kind of deterioration before on cheap o-rings. The kinks pictured showed that it was manhandled on install.







Frankly, the new gasket is EXACTLY the same as the one that failed. I expect to be doing this again next year given the level of deterioration observed which is extremely disappointing on account of having converted an 03 Evo 8 and a 91 Civic to e85 using all of the original gaskets and o-rings without this kind of failure. Hopefully, they revise the gaskets.

 

The gasket needs to be installed on the tank first, then the sender slid into it,preferably with some silicone spray. Doing it any other way risks damaging the seal as your old one shows.

 

It's the tank...
You can tell because you can see the fuel coming from the center of the tank and running down to the fuel level sensor/ pump

 

In my case, it was not the tank. The gasket fixed my issue. That doesn't mean the tank or the elbow may not fail on me as it has to others.