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65 coupe leaking fuel

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65 Coupe 289 v8. Normally, there is no leaking of fuel. However, if I let the car sit for a couple of weeks without starting (not something I do often), then upon starting, a significant amount of gas trickles from the fuel pump (about 1 cup). I have tried to pinpoint the precise origin of the leaking while it was happening, but I am afraid to let it run longer than about 15 seconds, so I am not sure. It seems to be leaking from below the point where the inlet and outlet lines are attached, but the screw-on canister containing the fuel filter is screwed very tight. If I start the car every day thereafter, the leaking does not happen. This has happened twice now. I have no qualms about replacing the fuel pump if that is the problem, but I am wondering if there could be some other issue at play here. Any ideas?

Putting a pan under the area and looking when it's leaking is the best way to find the issue.  But if you're not comfortable with that, then I would remove the filter canister and clean the surfaces the rubber gasket seats to.  Then before reassembling it, make sure the gasket is not damaged (replace it if it is damaged) and lightly coat the gasket and the seating surfaces with some Vaseline.  When you reinstall make sure that the gasket is not twisted or out of place. 

If that does not fix it, then it may be the rubber hose between the line that comes from the tank and the pump inlet.  It can dry and crack with age and leak (they swell and the leak goes away when fuel goes through them again), and the clamps holding it to the lines can loosen with time.  The fix for this is to replace that section of line.

Joe AZ 2 PA:
Being in the AZ heat doesn't help old car parts. Gaskets, hoses, etc. Sometimes the float will stick or if hasn't been replaced since the car was new may also be an issue. The leadfree E-10 gas isn't friendly to older parts that were designed for leaded gas.

Thanks for the suggestions. I was expecting the issue to happen the last time I let the car sit, so I did have a pan under it. My assessment at the time was that the leak was coming from "everywhere", not real helpful. The hoses are brand new and I checked the clamps-they are tight. Based on the responses, I think the gasket or seal from the filter canister is the culprit. I will get around to doing a thorough check in a few days. In the meantime, can someone explain why this would only happen when the car sits for periods longer than a few days? Thank you.

It may be drying out and shrinking.  I had a similar problem with the bowl gaskets on my Holley carb - they'd leak if I did not drive the car for a week.  The newer gaskets are rubber, I think, so maybe it's time to change the fuel filter (they come with a new gasket).


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