My '59 Nash say for a few months (ok, a year). I recently got it running again by changing out the spark plugs and fuel filter. We let it run for awhile, then shut it down.

That's when we noticed that the carburetor was leaking fuel from two places.

We cleaned up the fuel, then ran the engine again. This time no fuel leaked.

One of our crew guessed that the seals had dried out and shrunk with age and the fuel caused them to swell back to their proper size. Is this possible? If not, what could have been the cause?

  • It is possible that some crud was keeping the float needle open. It may have been cleared by the fuel flowing through it.
    – mikes
    Commented Mar 23, 2015 at 11:25
  • What part of the carb was it leaking from? As mikes suggests, could it have been overflowing due to needle valve not seating? I'm assuming this has a 1-barrell carb? Commented Mar 23, 2015 at 11:28

1 Answer 1


I think your crew member has a plausible explanation for the issue. I don't have any experience on a '59 Nash, not even close.

Most my comparible experience is with pre-80's motorcycles.

I have repeatedly seen carbs leak initially when putting fuel into a system that has been dry for a decade plus, they frequently have air leaks and fuel leaks.

It seems heat makes this 'work' bit better and allows the gaskets to expand with the fuel and heat and then a nice cool down squeezes out some of the fuel in gaskets and now they are moist and swollen and seem to hold.

I wouldn't go steady state with it though. I can't see it continuing to function reliably over time.

Most every time we are tearing everything down and doing a full rebuild.

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