Water in fuel - what now?

[TonyS]

I have just opened the screw at the bottom of the primary filter and there was a large teaspoonfull of water came out before the fuel. This is the first time in 5 years that I have found any water. What should I do? Remove the sender from the fuel tank in the photo in the post below and try and extract any water/gunge from the black plastic fuel tank using the Pela Vacuum extractor or should I buy some chemical from the Chandlers to convert any water/gunge back into fuel. What is the best course of action please?

 

[VicS]

[ QUOTE ]
What is the best course of action please

[/ QUOTE ] The BEST course of action might be to drain the tank, remove it, clean it and refill with fresh fuel, but I dont suppose you have that sort of remedy in mind. Therefore why not suck out as much water and gunge as you can with a Pela or similar then treat the fuel to deal with what is left.

 

[Cloven]

I had this problem a few seasons ago and dicovered that the rubber seal on the filler cap had perished and let water in through the winter.

Rather than mess about, I emptied the tank completely (fortunately I have a big fitting on the top that allows me to get my whole hand into the tank) cleaned out the tank and refilled with fresh fuel, replaced the sealing ring and not had a problem since.

I would have thought that this would be a pretty long job with a Pela extractor. The marina where we were based at the time offered to pump out the contaminated fuel through the sender hole and I would have gone down this route if I had not been able to access the tank easily.

Hope this helps.

 

[Robin]

Hi Tony. Obviously you have cleaned the watertrap filter and replaced any paper element so the next stage is to try and drain some off from the bottom of the tank itself. Many tanks will have a drain point at or very near the bottom and you can open this to run off some of the contents until clear fuel emerges, water sinks to the bottom so will drain off first. Probably there may be little present so not too much of a problem. If there is no bottom drain then maybe you can release a pipe connection low down to achieve the same result, otherwise if you can get to the contents via an access hatch or gauge sender then a long tube to syphon some off from the bottom might be plan B.

Did you fill the tank completely over the winter? A common source of water, other than dodgy fuel is condensation formed over the winter from air via the breather pipe.

The watertrap primary filter should be enough protection once you have checked the tank as above, I'm assuming that it is a proper watertrap type like a CAV or Racor?

Robin

 

[TonyS]

Hi Robin,
There is no outlet at the tank bottom, all the offtakes are from the top as can be seen on the photo on the preceeding post. I have just come back from the boat where I tried to remove the sender. Unfortunately, as the tank is full from the winter top-up, this is also under the tank level or the waves in the marina in this E F7 are causing waves in the fuel tank! Anyway fuel started to come out so I have given up. I assume that there must be water in the bottom of the tank to reach the level of the offtake but it may be only a pint or so. I therefore thought that if I removed that, and gave it a dose of chemical to clear any possible bug, that would be OK. It will now have to wait until I have done some motoring and I will check for water in the filter on a regular basis.

 

[rob2]

We had to drain the diesel tank to fit anew fitting at the base. around 90 litres came out in under a minute using an electric drill mounted pump. I was sold the idea that the flash point of diesel was low enough to remove the risk of ignition from the drill.

If you have access from the top and can chuck the fuel through a pump into a plastic dustbin, the separation can then be performed before returning the fuel to the (cleaned) tank. As the water sinks immediately to the bottom, pump it back with the inlet held well clear of the bottom. The last knockings can then be separated by hand.

 

[VicS]

[ QUOTE ]
I was sold the idea that the flash point of diesel was low enough to remove the risk of ignition from the drill.

[/ QUOTE ] "high enough" you mean. The F.Pt. of diesel is in fact around 62C so unless you heat your diesel fuel up to that temperature there is no problem with igniting it with the drill or any other potential source of ignition either.

Petrol by comparison has a F.Pt of -40C so its vapour can be easily ignited if it is anywhere above -40C.

Point of irrelevant interest -40C = -40F

 

[Robin]

It doesn't seem like a huge water problem and can be monitored as you say at the watertrap. Another possibility would be a pipe put down the filler hose, but that would only work if it was a straight one, which probably most aren't. Our filler hose goes the scenic route but fortunately we do have a drain plug right near the base of the tank. We had some water in the watertrap after the 2006/7 winter and drained about 50mls more out of the tank via the drain plug, that was all there was. We had left the tank about 5 gallons short of being full, apparently that was enough to collect some condensation. I didn't add any of the water absorbing stuff but I always use Soltron as a routine and this winter the filter was clean again with no water and no crud.

 

[vyv_cox]

I've never found the need to do anything about water in my fuel tank, fortunately. However, I have read several times in these pages that a Pela extractor had been used very successfully, not only to remove water but to remove diesel bug sludge as well. Assuming that you only need to remove the liquid below the fuel pick-up pipe you are presumably talking about 2 or 3 litres maximum? I would pull out a Pela full, decant it into a transparent bottle and see what settles out. If necessary repeat until only diesel remains. Then add Soltron.

 

[TonyS]

Thanks again to everyone for their input. I will try the Pela when I can get into the tank.

 

[nigelhudson]

If you do choose to drain the tank then I suggest that you pump out the diesel through the filter. As long as the flow rate is not too high this will trap almost all the water in the filter bowl - remember to check the bowl several times during the transfer.

 

[Heckler]

my bene has a white semi transparent tank, it has a std level transmitter screwed on to the top, i take this off and have a hole thru which i can see the inside of the tank, i have used a pela to chase little beads of crud and water to keep it nice and clean.
stu