BenjaminV

I have a Yanmar 2000. My fuel filter bowl keeps filling up with water and the problem is getting worse. Now, I can oly run it maybe 15 minutes before the filter bowl is over half full of water and the tractor will not run. I have completely drained the tank three times and when I do there does not seem to be any water in the fuel. I suspect I have a blown head gasket but I am confused about a couple of things. First of all, I don't see any water on my oil dipstick. Secondly, with a blown head gasket, I can understand water leaking into the cylinders but, would it get all the way back to the fuel filter? I do seem to be losing some coolent. Is there any other way that water could get from the cooling system to the fuel system? There are a couple of diesel mechanics around here but I would at least like to have an idea of what the problem is before I call them.
Thanks,
Ben

winston

This is a good one. I know you said you drained the tank 3 times but hard to believe water can come back through an injector pump and into the fuel filter. I suppose anything is possible but this is stretching it. Only one other way for it to get into the tank and that would be through the bleed lines on the injectors that go to the thermostart reservoir and from there to the fuel tank. Pretty sure the 2000 doesn't have that setup so I doubt that scenario also. Did you just let the tank drain through the hose the 3 times? I'm thinking maybe some water is just trapped in the tank and when you start back up and move around maybe trapped water is making its way through to the filter?

Now as for the head gasket. Does your 2000 have an overflow bottle? Many times blown head gaskets will cause compression to leak into the cooling system and if bad enough it will blow enough to force water into and out of the overflow bottle. Best check for that is to crank your tractor cold and watch the overflow bottle for bubbles. A constant stream is a blown head gasket. If you don't have an overflow bottle just remove the radiator cap and run tractor cold watching for bubbles in the radiator.

BenjaminV

I just drained it through the line that goes to the filter. Is there another way of doing it? I just don't think the water is coming from the tank. The last two times I drained it I ran fuel through it before I hooked the hose back up. I agree it doesn't seem like the water could go backwards through the pump but it is coming from somewhere. I'll mess with it some more tomorrow and see if I can figure anything out. As I mentioned before there does not seem to be any water in the oil or oil in the water.
Thanks for your help.

Ben

winston

No other way except back through injector pump or from injector bleed offs. Here is a picture of the injector bleed back through the thermostart bottle and then to the tank. The little rubber hose coming off the injectors go to the thermostart bottle and then back to the fuel tank. I don't think your 2000 has that setup but it might. Still hard for me to believe water could come back through the injector pump. As far as I know those two routes are the only possibilities of water coming from the engine to the fuel filter.

Does your tractor run smooth until the water over comes it?

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BenjaminV

I'll drain it again tomorrow and try to dry it out with an air compressor. After I drain it and bleed the lines it runs real well until the filter cup gets about one third filled with water. I must not be getting all the water out of the tank.
Also, if I bought fuel with water in it, wouldn't it separate in the can? I guess it is possible that I've bought bad fuel two times in a row, since I always buy it at the same place but lots of people buy it at the same place so if it was comtaminated I think there would have been fixed by now. So I'll try it one more time tomorrow and dry it out with compressed air.

winston

Maybe it will work this time. Let us know.

ErnieS

The hose running from the tank is most likely an inch or so from the bottom. Draining the tank from there would leave water and or fuel below that outlet. As soon as you move the tractor, the fuel is moving around and some of that water will get sucked out and into the filter. Be happy the filter is doing it's job and keeping water out of the injectors.
What I would do, is drain the tank as you have been, plug the outlet and remove the tank. Pour the rest of whatever is in there into a bucket and check for water.
Clean out the tank well with soapy water, rinse and dry with compressed air.
Check the fuel you drained for water and reinstall the tank and fill with good fuel. Bleed as usual and take her out for a spin. Check the filter after 15 minutes and get back to us.

If you know someone with a gas station, see if they'll give you a bit of the paste they smear on their tank sticks. The stuff changes color when it contacts water. Smear some on a clean dowel that will reach the bottom of the tank. I bet you have an inch of water laying in the bottom

ErnieS

Kolor Kut Water Finding Paste

partsman

Same thing happened to me. Drained, filled, drained, filled. Finally drained the tank right, emptied the fuel bowl, drained the lines, replace the fuel bowl with a new one and new oring. runs like a champ now.

If you ever need parts for your yanmar, check out Best Farm Parts - Replacement Parts for Tractors and Farm Implements. if you don't see it on the website, email them. They respond quickly and can get the parts for all those old yanmars out there.

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http://bestfarmparts.com

BenjaminV

Thanks for alll the adcice. I think I have it fixed but I had to have emergency surgery on the 18th, so I haven't had a chance to even start it. Will let you know when I do.
Thanks again,
Ben Voiles