New to FDs, but done a couple thousand miles in it so far, with a bunch of fills.
I filled up over the weekend (it's Texas, so HOT), and topped up a little after it auto-stopped (don't usually do this).
I drove about 5mins, then stopped at a store.
Came out of the store to a puddle of fuel dripping off the back side of the fuel tank.
After spending 15mins or so laying on the blazing concrete, I couldn't find any source of the leak.
I washed it off, pushed the car out of the puddle and drove fairly sedately home.
It hasn't leaked since.
Looking at parts diagrams, a possible culprit looks like maybe the separator or vapor valves?
Not super keen on dropping tank to look at it, but will if I need to.
Anyone have any ideas, or seen this before?
PS. I now have a fire extinguisher in the car.

 

Back side of the fuel tank - presumably that is along the bumper and not the subframe.

There's an access panel for the fuel pump on top of the tank. I'd start by removing that and looking for any witness marks of fuel leaking from the seal between the fuel pump assembly and tank. The seal could have gone bad. They get hard over time.

Next, try to check the main hose between the filler and the tank and the associated overflow hose. Maybe they aren't properly attached, loose clamp, hard, brittle hose that doesn't seal anymore etc.

Could also be the other items you mentioned. Can't hurt to check them all for your own safety and peace of mind. These parts are 30ish years old at this point... you might as well contemplate replacing all the old hoses and clamps if you drop the tank.

 

When you top up too much, the fuel fill cap can barf some fuel out as it warms up. Fuel in an underground station tank is likely around 55F, and if it's 95F out, it will expand a lot, so it could be as simple as that.

 

I'm pretty sure the tank & lines were replaced before I got the car.
I couldn't feel/see any moisture anywhere except right at the back/top of the tank where it was dripping down, right in the middle. Around the X/Y area in the diagram above from what I can tell.
I'll have to find some time to drop the tank I guess.
Definitely wasn't coming out of the filler/filler vent. That was the first thing I checked, and I could jam my hand in there & feel around that area.
Thanks

 

If the leak seems to be located on the top rear, and the PO replaced the tank and lines it’s possible he just didn’t seal, or crimped the seal on the fuel pump access. Could be something as simple as a new gasket.

 

^This, or it could even be as simple as a poor hose connection on the fuel lines on top of the tank (pressure out & return)

 

There aren’t too many connections with the fuel tank that could leak like that. I had a similar issue but it was coming from the fuel fill hole. If it is coming from the fuel fill hole where the gas cap goes, could be bad vents, there are two, can only clearly get to them by dropping the tank. Or like everyone else said could be a loose line. Take out the fender well of the rear tire and it will reveal the vent hose from tank to fill neck. Make sure that’s not cracked or loose as well. Also as previously stated pop the top hat inspection cover off and see if it looks like it’s leaking there.