Channel Sailor
Well-Known Member
On both Yanmar 2GM20s I have owned I had trouble with slight weeps of fuel from the bleed screw on top of the engine mounted 2nd fuel filter. Usually the problem commencing after servicing. I would recommend a new copper washer each time anyway. But today even with a new washer and four or five attempts I still had a very slight leak. Also I was out on a swinging mooring so only a few spares and tools.
My tip to fix it is to fit a new dull copper washer and tighten down as normal. Then remove the washer and rub it each side on fine wet and dry paper laid on a firm flat surface to start to polish it up. Now look closely at the washer each side and you may see evidence of the scores on the mating surfaces and these scores if present may not even all around.
This led me to inspect very closely the mating surface of the securing screw, which I discovered was not perfect (A Swiss Army knife magnifying glass would have helped here) To remedy the problem I made a small hole in the fine wet and dry paper and placed the screw threaded part through the hole, then placed a close fit washer over the top to press the wet and dry paper evenly onto the mating surface. Apply pressure and twist around the paper and washer together for a good few times to clean up the mating surface. I also very very carefully cleaned the mating surface on the filter assembly
Clean the parts, reassemble with another new copper washer. In my case, this fixed the problem. I also warmed the washer first and the engine was warm.
This also avoided overtightening the screw to overcome any roughness on the mating surfaces. Remember to throw away the old scored washers.
My tip to fix it is to fit a new dull copper washer and tighten down as normal. Then remove the washer and rub it each side on fine wet and dry paper laid on a firm flat surface to start to polish it up. Now look closely at the washer each side and you may see evidence of the scores on the mating surfaces and these scores if present may not even all around.
This led me to inspect very closely the mating surface of the securing screw, which I discovered was not perfect (A Swiss Army knife magnifying glass would have helped here) To remedy the problem I made a small hole in the fine wet and dry paper and placed the screw threaded part through the hole, then placed a close fit washer over the top to press the wet and dry paper evenly onto the mating surface. Apply pressure and twist around the paper and washer together for a good few times to clean up the mating surface. I also very very carefully cleaned the mating surface on the filter assembly
Clean the parts, reassemble with another new copper washer. In my case, this fixed the problem. I also warmed the washer first and the engine was warm.
This also avoided overtightening the screw to overcome any roughness on the mating surfaces. Remember to throw away the old scored washers.
