Diesel in the Bilge

Doing an ER check this morning which includes checking the mid ship bilge. Found about a quart of diesel in there.

I got it all cleaned up and checked the engine and genset pans etc and couldn't see any sign of a leak. Same with the lines and valves.

I started the engines and let them run for a half hour, no drips or leaks anywhere. Did the same with the genset.

The only thing left is the fuel transfer pump. I transferred fuel to balance the boat two days ago. I am thinking that the pump is leaking and after I finished and reset the valves back the fuel in the transfer pump lines drained out. The amount would be about right.

Thing is, the only way to prove that is to transfer some more fuel, then sit and watch the pump, downside is another quart of fuel in the bilge.

I can balance the boat by alternating which tank I run from, so I am thinking of just not using the pump until I get home. Or if I happen to be in a marina with a yard (as I was over on York River) I may test the pump since I can dispose of the fuel and then have someone replace the pump if needs be.

If you sit there to watch for a leak while transferring, you shouldn't have to end up with another quart in the bilge. Plus, you need to find the source, right?

When my pump leaked it was quickly obvious. If you put a container under it you could use it when stopped, not rolling, if necessary.

kchace said:

If you sit there to watch for a leak while transferring, you shouldn't have to end up with another quart in the bilge. Plus, you need to find the source, right?

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Depends if it starts leaking right away or if it needs to get up to pressure with filled hoses before it does so. If the latter then I am mopping up diesel again!

bayview said:

When my pump leaked it was quickly obvious. If you put a container under it you could use it when stopped, not rolling, if necessary.

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It's on the floor so no place to put anything under it.

I had a leak through my fuel cooler.

90 degree elbow fitting on right looks damp.

When looking for a leak, take a dry white paper towel and start dabbing around. You should see a pinkish color on the towel when you find a little residue from the red dyed fuel. Sniff the towel also as diesel is pretty fragrant and easy to detect.

Ted

O C Diver said:

90 degree elbow fitting on right looks damp.

When looking for a leak, take a dry white paper towel and start dabbing around. You should see a pinkish color on the towel when you find a little residue from the red dyed fuel. Sniff the towel also as diesel is pretty fragrant and easy to detect.

Ted

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A piece of brown cardboard works better, since once it gets wet, it gets dark.

Ok main issue found and easily resolved (if working in a hot ER is ever easy), but I have a resultant question.

I set the valves for transfer and turned the pump on. Pump was leaking out of the front brass plate.

I got the camera on the plate and it is held by three screws. So I got my ratchet set out and tightened them. Two were a little loose, the bottom one was pretty loose. I guess from the pump's vibration.

Turned it back on and no leak.

However no fuel being transferred either. It is a self priming pump but the label states that if there is air in there the air will need to be purged. Clearly there is air since the fuel drained out.

So question, do I need to take the "out hose" off the pump and run the pump until fuel comes out, or can I start an engine or the Genny leaving the valves for the pump open and the pump on for a while and let the engine pull the air through? Will a pump full of air affect the engine?

If you suck the air through your main engine or generator, they will stop. Don't do that!!! Does the tank suction come off the bottom or top of the tank?
If bottom, line it up to transfer to a fuel tank, and pump away. If the top, then the cover gasket may be leaking air in on the inlet side. Try going in reverse direction. Fuel would then squirt out the leak.

High Wire said:

If you suck the air through your main engine or generator, they will stop. Don't do that!!! Does the tank suction come off the bottom or top of the tank?
If bottom, line it up to transfer to a fuel tank, and pump away. If the top, then the cover gasket may be leaking air in.

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Not sure I understand that. The pump won't prime and pump until I get the air out, is the only recommended way to take a line off and pump until I get diesel coming out?

The pump says self priming right on the end plate. Open the valves and turn it on.

menzies said:

Not sure I understand that. The pump won't prime and pump until I get the air out, is the only recommended way to take a line off and pump until I get diesel coming out?

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If the fuel tank suction comes off the lower portion of the tank, the pump will gravity fill to the pump casing. Start the pump and any remaining air will be pushed out of the pump into the destination tank.


If the fuel tank suction comes off the top of the tank (via an internal tube to the bottom) then the suction side needs to be air tight. This type pump will pump air as well as liquid as long as the suction and discharge path is lined up for flow. Pumping air takes longer to suck the fluid up the tube. The fuel must go up and over the top of the tank before it can reach the pump. If air leaks in, the fuel won't make it over the top.

As long as you have an open flowpath on the outlet to a tank or a bucket, and an air tight suction path, the pump should self-prime eventually.


If the pump casing gets warmer than the fuel, its not pumping.

Does the fuel line feeding the pump come out of the top or the bottom of the fuel tank? Is the fuel level in the tank above or below the pump?

Ted

Those vane pumps are not as good at self priming as rubber impeller pumps but should be good for a 3 or 4 foot lift. Yours may just be getting a little worn. I’d try taking the face plate off and putting a very light coat of grease on the inside of the pump and on the inside face of the face plate. Don’t get grease on the blades where it might cause them to stick in the Rotor. Get yourself a set of blades, gasket and rotor to have on hand when you need it.

Ok, I see what you are saying now.

The feed is from the bottom of the tanks and the pump is below the bottom of the tanks. Right now I have both the to and from pump fuel valves closed which is the way they are when running. I need to open those and let gravity do it's thing on the fuel and hope that the air is pushed up into the tanks.

The label attached to the pump states that it will not run unless bled, so see will see.

A strip of paper towel can be tied to most items/fittings , in a day or so even a tiny leak can be found.

stubones99 said:

A piece of brown cardboard works better, since once it gets wet, it gets dark.

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FF said:

A strip of paper towel can be tied to most items/fittings , in a day or so even a tiny leak can be found.

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Cheap brown napkins, like the recycled kind you get at a deli or fast food place, often work better than higher quality white kitchen paper towels. They keep their discolored look and stay deformed from the moisture.

Diesel around here gets dyed red, so there's that trace color that helps, but looks like yours wasn't?

It is red as it has to be across the US for all off-road use for tax reasons.

P10 Master Rebuild Kit

I have just had the same problem on my GA60. Same pump. Ordered the rebuild kit and installed. Piece of cake. Also noticed a good bit of wear on the inside of the face plate. Used a small block of 1x2 with emory cloth to sand the plate smooth. Not perfect but, much better than it was. Aslo, lightly sanded the face of the pump housing where the face plate sits. Replaced every part in the kit except the rear seal that goes in the very back of the pump housing. It looked like you'd have to remove the pump from the motor to get at that one. Lite o-ring grease and no leaks..... Pump worked immediately..... once I got the valves set correctly.... All Good! 30 minutes tops....