Thanks to everybody for the helpful information posted here. Here's how this info helped me today.
I bought my car a few months ago. It's in fantastic shape except for one thing: the car stinks of gasoline whenever I accelerate or make sharp turns with a full tank. (This explains why the tank was nearly empty when I test-drove it.) I did some sleuthing that led me to the passenger-side
fuel pump. Wet gasoline around the white plastic tank lid confirmed that gasoline sloshes in the tank and leaks around the lid.
Records show that a dealer previously replaced the
fuel pump, so I suspected that the mechanic didn't get a tight seal around the lid when it was reinstalled.
I bought a new gasket ring and the recommended cover removal tool from
amazon (hint: that tool is absolutely worth the $13 I paid). After I unscrewing the ring, I discovered that the cover gasket was perfect, but the threaded ring was split. I suspect that the previous mechanic cross-threaded it and tightened it until it split around its perimeter. If you don't have a strong light and an inspection mirror, you can't see the split, so I understand that it could be an innocent mistake.
I bought the replacement ring and followed the advice in this forum to remove the fuel lines, replace the gasket (it looked good but I had a new one), and installed the new threaded ring.
REINSTALLING THIS RING IS VERY DIFFICULT. It's insanely likely that it'll get cross-threaded the first 3 dozen times that you try. Here's the technique that finally worked:
- Prepare yourself with great peace of mind. You will need it.
- Get the cover plate centered exactly with its lock tabs properly seated.
- Have my husband* use a broom handle to push down on the white cover plate to hold it in place (his hands are too big to work within the tiny confines of the access hole, so he got the easy job).
- Note where the start of the threads are on the tank and the ring. Rotate the ring so that the threads are ready to mate.
- Carefully and repeatedly try threading the ring onto the tank. Beware that it will probably be cross-threaded.
It took probably 30 minutes of trying and retrying before the ring threaded properly. You can tell when this happens by verifying that there is consistent clearance all the way around between the threaded ring and the cover plate. Once I confirmed that the ring was properly threaded, I used the tool to tighten the ring snugly.
The gasoline smell is completely gone. Thanks to all the commenters here who provided helpful tips!