I am having a problem with diesel fuel in my bilge (1986 Catalina 27). The service dept. at the marina has replaced all of the fuel lines and fuel filter. All around the engine looks dry. One of the puzzling aspects is that if we motor out of the slip to sail and then return, the bilge is clear of fuel. When we come back one or more days later, fuel appears. It seems to be a mystery to everyone involved. Any guesses?
Diesel fuel in the bilge
- Thread starter zekeflash
- Start date
Could it be coming from the bottom of the fuel tank ? Tank leaks usually seem to start very small.
Could be, but wouldn't that show some kind of fuel around the tank...unless there are "weep holes" in the floor beneath the tank (?) [assuming a "false bottom"]
I have no answers, but I have some questions that might help you track this down. When you leave the boat do shut off the fuel at the tank? Does that have any effect on the amount you find in the bilge? Is it possible that when they replaced the hoses, they spilled some fuel and it's taking a while for it to migrate into the bilge. Is it pure fuel or a mixture of water and fuel?
Taking this right out into the Twilight Zone .............. any chance the running engine could be opening up the leak but is hot enought to evaporate the fuel, hence no fuel is visible when you return to port. After sitting and cooling for a few days, the leaking fuel now finds its way to the bilge and reveals itself.
Try wrapping/taping paper towel around the new hose fittings and filter that were altered during the last maintenance. Check them for smell, wetness, staining after a few days.
The above theories, along with $1.50 should get you a cup of coffee in any cafe.
Good advice. The one thing NOT mentioned is: you had somebody else do the work! Check every single hose clamp, every single one.
Many new boats come out from factories with LOOSE hose clamps. Wrench monkeys are not to be trusted.
Good luck.
Many new boats come out from factories with LOOSE hose clamps. Wrench monkeys are not to be trusted.
Good luck.
Fuel tank is probably under the starboard quarter berth -- and just above and to the right of the bilge. My guess is that the tank is the culprit here.
The tank on my C27 leaked. There was a pinhole leak from rust under the tank where it rest on the webbing pads under the straps. The tank appeared to be in great shape until I removed it. I towed the boat for half a day. When I got to my first stop, hoping to sleep in the cabin, I was overwhelmed with gasoline fumes from the gas that ran down the hull and covered the sole by a couple of inches. The gas leaked from the fuel compartment thorough the seals around the tubes that pass through the bottom of the compartment.
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If it's not the tank, then check the mechanical fuel pump on the engine. If the diaphragm on that pump is past it's prime that pump will likely leak.
I replaced mine this spring and got rid of a long standing leak. he cost of the pump (Yanmar part) was quite reasonable, under $100.
Cheers
Matt
I replaced mine this spring and got rid of a long standing leak. he cost of the pump (Yanmar part) was quite reasonable, under $100.
Cheers
Matt