Ask the Mechanic

Leak in a Fuel Line

(Steve Thompson)

READER: I read one of your earlier columns about a Ford 3000 tractor that had a Simms injector pump. I have the same pump on my Ford 3000 tractor, but mine has a problem. After it has not run for a week or so, it's extremely hard to start. It runs fine after it starts but is hard to start if it is not started every day or so. What do you think is the problem? There is no external fuel leak anywhere.

STEVE: More than likely this problem (tractor manufacturers call it an opportunity) is caused by the fuel being siphoned down by a leak in a fuel line. The leak is so small that fuel will not show up externally but just enough for the fuel to sneak by the internal fitting.

Usually, the leak on your tractor is found at the connection where the fuel line fits on the bottom of the transfer pump (see the photo accompanying this article). There is a special rubber sealing ring that seals that connection. A regular "O" ring will not seal this fitting. The top fitting on the transfer pump is usually made to seal with a factory metal fitting.


-- Write Steve Thompson at Ask The Mechanic, 2204 Lakeshore Dr., Suite 415, Birmingham, AL 35209, or email, and be sure to include your phone number.


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