scottw

iTrader: (1)

So I have the motor out of boat for rebuild and found gas in bilge. Cleaned it up and went back in about 3 weeks later and another puddle of gas in bilge. Set up a test rig, blocked off fill and vent tube at the tank and threaded line into pick up hole with tee gauge valve. Was putting air into tank and when it got to 1psi there was a lot of creaking from the tank expanding so I bailed out. I guess my question is would there be any type of check ball or something in fill tube? Also did I set up my test correctly? I think the tank is leaking for sure because even at that 1lb. When I closed the valve it lost pressure pretty quickly. Going to check all my connections with soapy water for leaks so I can rule that out. Should I try to get the air in quicker to get to the 3-4psi test pressure? Started out with a air brush compressor and then got out my big compressor and set pressure to 20lbs. for filling but like I said I stopped at 1psi.

Thanks for any input in advance.

mrv8outboard

There should be an anti siphon valve on the supply line. Do not use any more than like 3 PSI to test the tank. There are very few reasons to have fuel in the bilge. If you have not spilled any, have a leaking hose(fill,vent or supply) or the sending unit gasket has failed, you have a bad tank.

mrv8outboard

Also a vacuum test would work as well.

Unlimited jd

iTrader: (5)

An emissions smoke machine for evaporative emission systems works well also

scottw

iTrader: (1)

I should be able to pump my air into the tank tho correct? The anti sipgon line would be on the supply line and not the tank itself?

mrv8outboard

It is usually the barbed nipple fitting at the 90* fitting on the siphon tube.

f_inscreenname

Finding gas in the bilge. Start thinking about a new tank.
All the sending units and fills and such are in the top of the tank. Unless you have it's super full and its been hot out these things will not leak.

scottw

iTrader: (1)

Thanks everyone for all the responses. I guess I've been in leaky tank denial. Lol.. It looks like I will pull the bolsters and the back seat and pull up the carpet. Maybe there will be a panel over the tank but I doubt it being a 1990 boat. Any tips anyone can give to make this project as painless as possible?

wannabe

Scott:

Let a qualified boat yard do the tank repair/replacment. It all depends what kind of tank (alum, galv. steel, fiberglass, etc) you have. This is nothing to fool with. Knowing how to repair the bedding that holds the tank properly and glassing it in is tricky if you do not do this work normally.

Wannabe

scottw

iTrader: (1)

Thanks for the advice wannabe but the tank is 23yrs. old as well as the boat and I am replacing with new tank and going to tackle this project myself. Have a good idea on the project. Just looking for some tips on things to make the job easier, if there is a easy way to do this.