I have a 2001 S-Type.

I get a strong smell of fuel after I fill up the tank, but it dissipates over the next few days as the tank level decreases. I researched this issue on this site and ordered the seals and locking ring for the fuel sender units on top of the tank.

I filled it up today and took a closer look. The top of both of the fuel sender units and the tank looks dry, so it doesn't seem like fuel is leaking from around the ring.

But there was a little fuel in the sump area on one side below the fuel line. I wiped it out and within a few seconds, there'd be another thin layer of fuel collecting in the bottom. Not a lot, but I'm getting tired of the fumes!

I'm having second thoughts about messing with the locking rings. Any thoughts on how to seal this other area? Thanks for your help!

 

That's what I'd regard as a big leak and serious hazard so would fix it / have it fixed.