Fuel leaking in to bilge during fill up only

[fishon71]

I have a 1988 Sea Ox 18? dual console (awesome boat) I have owned it for 4 years and it?s a beast. This year I started getting fuel in the bilge when I fill it up and its getting worse. It has a 50 gallon internal aluminum tank. All fuel lines are double clamped and seem tight, no signs of leaks at those connections. I don?t see any leaks on the top side of the tank and there is no leakage after the initial fill up.

So I pulled the floor to get at all the hoses, fill & vent and pull them out. I thought for sure I would find a crack or something obvious in one of the hoses. The vent lines seem fine. The fill line was a bit dried out and cracked. All lines are 20 years old and probably not designed for ethanol blend. I filled the hoses with water thinking for sure I would see a leak dripping some place but I didn?t see any leaks. On the fill hose were it does a 90 degree to the tank it appeared pretty dry rotted and stains of possible leakage.

Do you think perhaps the fuel would penetrate through the hose and not the water?

What should I do next?

I plan on replacing all the hoses of course but I really like to know if that is really the problem. I also thought of trying to pressurize the tank some how.

 

[tashasdaddy]

Re: Fuel leaking in to bilge during fill up only

you are way past due for hose replacement, you can put about 4 psi on the tank to check for leaks, use soapy water, on all sides, and seams.

 

[gcboat]

Re: Fuel leaking in to bilge during fill up only

Yup, gas will leak through a hose before water will. Now, does the gas still go into the bilge after you fill up or just during the actual fueling process?

 

[fishon71]

Re: Fuel leaking in to bilge during fill up only

How does one pressurize a tank like this? I have a 1 1/2" fill hole and two 3/4 vent holes in the tank. For the amount of fuel I'm getting at fill up it should be a pretty obvious size hole.

I mop up all the fuel with paper towels before we go out, so the bilge is dry. I would also think when at sea and the gas is splish splashing around I would get some more in the bilge if the tank was leaking, but I don?t.

I see on the fill line it is special coast guard approve hose, does it go for the same with the vent lines. Do I have to buy all this material at the marine store?

 

[gcboat]

Re: Fuel leaking in to bilge during fill up only

Let's forget about pressurizing the tank for now- doesn't appear to be your problem.
Yes, the main fuel fill hose should be USCG approved, not necessarily the vent hose - but it wouldn't hurt it to be.
My local NAPA carries the fill hose so if you have one close to you might want to give them a call. However WM carries all that you will need and they will honor the NAPA price ( imagine that ? ).

 

[fishon71]

Re: Fuel leaking in to bilge during fill up only

Ya, I just measured the hoses to get an idea on what this will all cost. I found the 1 1/2" A2 for $7.99 per foot on line and I need a 6 foot piece. I will make some calls this week local. The vent lines are 5/8" and I'm going to replace everything from the tank to the motor also.

Just wish I could see a hole in the line some place!

I guess I will replace everything as it is needed anyway and buy some fuel to top off the tank for the winter and see if I get any splilage in to the bilge.

Who ever thinks of replacing fuel lines on an old boat until there is a problem? I guess I'm lucky the problem was not bigger, like a boom!

 

[gcboat]

Re: Fuel leaking in to bilge during fill up only

Good luck to you - it will be money worth spent.

 

[fishon71]

Re: Fuel leaking in to bilge during fill up only

Can someone advise if there is any adhesive or special tape used at the hose tank connections or do you just clamp it tight with hose clamps?

 

[Bondo]

Re: Fuel leaking in to bilge during fill up only

or do you just clamp it tight with hose clamps?

Ayuh,.... Nothing Special there.....

Some folks will double clamp them, but it's not necessary....

Just be sure to loop your vent lines Up, before dropping down to the tank.....
It keeps the water out.....

 

[reelfishin]

Re: Fuel leaking in to bilge during fill up only

I redid the fuel fill hoses in a Hydrosports 23' last year, instead of going with all rubber, I made up aluminum tubing to span most of the distance. That way I only needed two pieces of 1.5" hose at each end. I also was able to find a silicone rubber based hose that was rated for ethanol as well, not CG approved I suppose but it was meant for aircraft fuel, so I doubt it will fail in my lifetime. By using aluminum tubing, it saved me a bundle in hose costs. I considered using stainless tubing but didn't like the idea of the added weight and figured that the aluminum tube will outlast me. (The old rubber fill tube was in there since 1973 and only just began to leak).

I did paint the tube heavily on the outside for some additional protection. Mostly since it lays directly in the flotation foam most of the way to to the tank. I figured that with as much work was involved in getting to that fill tube and tank, I didn't want to ever have to do it again. I also didn't worry much about the tube being aluminum vs stainless since the tank is also aluminum. I did add grounding tabs to the tube to help prevent any static electricity build up and the fill cap ring was also grounded.

 

[fishon71]

Re: Fuel leaking in to bilge during fill up only

Called my marine store and he says type A1 hose is better than A2. What I took out was A2 and seemed that's what I should put back.

Does it mater if I use type A1 or type A2 fill hose, what is the difference?

 

[gcboat]

Re: Fuel leaking in to bilge during fill up only

Here's your answer:http://www.uscgboating.org/safety/boatbuilder/fuel/183-540-a.htm

 

[fishon71]

Re: Fuel leaking in to bilge during fill up only

Okay, that answers that, looks like A1 is a better hose if I read that right!

Thanks

 

[dingbat]

Re: Fuel leaking in to bilge during fill up only

I redid the fuel fill hoses in a Hydrosports 23' last year, instead of going with all rubber, I made up aluminum tubing to span most of the distance. That way I only needed two pieces of 1.5" hose at each end. I also was able to find a silicone rubber based hose that was rated for ethanol as well, not CG approved I suppose but it was meant for aircraft fuel, so I doubt it will fail in my lifetime. By using aluminum tubing, it saved me a bundle in hose costs. I considered using stainless tubing but didn't like the idea of the added weight and figured that the aluminum tube will outlast me.

It seems the Feds don't think it's such a good idea.

FEDERAL LAW

183.538 - Metallic fuel line materials

Each metallic fuel line connecting the fuel tank with the fuel inlet connection on the engine must:
(a) be made of seamless annealed copper, nickel copper, or copper nickel; and
(b) except for corrugated flexible fuel line, have a minimum wall thickness of 0.029 inches.



If metal is used for any portion of the fuel line (except for fittings) from the tank connection to the engine connection (usually at the fuel pump), the metallic fuel line portions must be seamless, annealed:

(1) Copper;
(2) Nickel copper (Monel); or
(3) Copper-nickel.

No other metals are permitted.

Also, the thickness of the tubing wall must be at least 0.029 inches unless the fuel line portion is a corrugated or accordion type of flexible fuel line. Tubing is available with thinner wall thicknesses, but they SHALL NOT be used.

Metal fuel lines used on the engine, i.e. the fuel line from the fuel pump to the carburetor, may be made of materials other than those listed. This line is usually supplied with the engine.

http://www.uscgboating.org/safety/boatbuilder/fuel/183-538.htm

 

[dingbat]

Re: Fuel leaking in to bilge during fill up only

I redid the fuel fill hoses in a Hydrosports 23' last year, instead of going with all rubber, I made up aluminum tubing to span most of the distance. That way I only needed two pieces of 1.5" hose at each end. I also was able to find a silicone rubber based hose that was rated for ethanol as well, not CG approved I suppose but it was meant for aircraft fuel, so I doubt it will fail in my lifetime. By using aluminum tubing, it saved me a bundle in hose costs. I considered using stainless tubing but didn't like the idea of the added weight and figured that the aluminum tube will outlast me.

Using aluminum in a fuel system probably isn?t such a good idea. Aluminum and seawater don't get along very well. Especially if you have it buried in a place that has a tendency to retain moisture.

Hope you at least used 5052 aluminum tubing. Silicone Rubber and unlead gasoline is a no-no as well. Hopefully they where some kind of a polyurethane compostion