Fuel leak while fueling at the tank - problem & solution

[DeLorean]

When Ever I fueled the car, topping it off or even coming near the top caused a massive fuel leak.

I had initially suspected that the filler neck rubber hose was bad in some way. Upon investigation, I found that part 47 in this diagram-
http://www.delorean.com/store/c-274-2-1-0-tankhosespumpaccumulatoretc.aspx

Had turned to mush. Maybe the ethanol fuel, maybe just age, but the rubber had simply degenerated and was allowing fuel to leak right past it.

Additionally while I was in there I found that the fuel pump assembly ring terminals were highly corroded and likely would have caused a break down shortly. I replaced the ring terminals, replaced all 3 O-rings (Check valve & Both Banjo bolt rings) and the original pump still worked fine and I was able to salvage.

New boot, new ring terminals, and no more fuel leak

[T_Stanley]

I had the same problem with my (former) D. The leak eventually stopped after about a minute, but it was annoying as hell

[TTait]

I had a similar problem too... I try to inspect the fuel pump every year or so now.

[WelmoedJ]

There is another part that may start leaking when topping off the fuel tank (i.e. if you fill up to the neck).

That's the fuel sender. Some of the series 1 and 2 of DMCH seem to have a leak through the wires on the top of the sender. You will not detect that leak if you don't overfill the tank, but if you do it's noticeable as fuel leaks on the floor under your car.

Improper installing of the fuel pump boot and its clamp also may result in leaking fuel when overfilling the tank.

Welmoed.

[DMC3165]

Improper installing of the fuel pump boot and its clamp also may result in leaking fuel when overfilling the tank.

Welmoed.

This happened to me and was scary as hell the first time I saw gas pouring out from under the car. Worst part was it took several tries to properly line up and reseal the boot and clamp because the clamp was tightened on an angle and warped the rubber. Eventually I finally got it when I removed the spare tire and trunk floor, readjusting the entire pump, and watched it while I topped off at a gas station. IMHO this setup could've been designed a little better.

[WelmoedJ]

Yes, you're right; it could have been a better job.
But.... it has been over 30 years ago and we still "live with it".

The new boots and dust covers are of better design and quality and John Hervey also sells a better type of clamp (not the small ones originally on the car).
Together with the three-legged boot support bracket is can be set up safely.

You only have to make sure yourself it's done properly.
For some that takes trial and error sequences.
Learn while doing however is often the best way as I also found.

Welmoed.