Diesel fuel tank leak

Risingson

Active Member
Jun 12, 2020
182
Cos cob ct
Boat Info
1999 410 express 3116’s
Engines
Cat 3116 350 hp
Looks like I have a pin hold leak in my starboard tank. Found a little fuel dripping from under the tank. Going to be a big problem I would assume. Any ideas?
 
Many years ago I learned a TEMPORARY FIX from my father.

Find the spot and rub a bar of FELS NAPTHA SOAP into the area.

NOT A PERMANENT FIX, but it may hold it while you determine your next step.

BEST !

RWS
 
i'"Looks like I have a pin hold leak in my starboard tank. Found a little fuel dripping from under the tank. Going to be a big problem I would assume. Any ideas?"

I've see fuel tanks replaced on 410DA's and on 450DA's. It is an expensiove and time consuming task on both. The cause is usually moisture from leaks in the deck plate O-ring seal or condensation in the tanks from failing to leave the tanks full in the off season.

The tanks in the Sea Ray Sport Yachts were made and on labor and tank cost.furnished by Florida Marine Tanks. They still have the drawinmgs and specs for the tanks and t hey will still make replacement tanks. This is kind of a slam dunk because their tanks fit exactly and have all the correct fittings on them. The problem is they used to treat Sea ray owners very well on pricing but when Sea Ray closed the yacht divisions it hurt prime vendors like Florida Marine Tanks so pricing reflects that.

On a 410EC I suspect you will need to pull both engines and transmissions and perhaps the cockpit deck so you can expect several days in a boat yard plus 2 men for about 40 hours each coming out and close to the same going back in. This is going to be expensive unless you get some help on pricing from your yard and service center.

Sorry, but there are very few short cuts possible on a fuel tanks replacement of this size.
 
Run off one tank for the rest of the season. When I replaced mine I had the new one made 1” smaller. I was glad I did because sliding it in was a pain in the butt
 
Thanks Frank …uhh I’m disgusted. I was hopeful
For a sealant that could be placed in the tank somehow. tanks have always been full for storage and never have had any water intrusion.
Riptide did you have to remove the engine and floor?
 
Sorry to hear. Because metal tanks corrode you could consider semi custom rotomolded tanks from Ronco Marine Tanks. They come in many sizes and place whatever fittings you want wherever you want. Their pricing is very good and will never corrode. You could connect two smaller tanks or have a straight in fill hose to permit use of a fill dip stick. The did the holding tank replacement on my sailboat and shipping was very fast.
Firms that remove old home heating oil tanks by cutting them up might be able to do the same for yours.
Good luck.
 
The starboard tank on mine was replaced by the PO for the same reason. I can pull the invoice for you and send a copy if you'd like. The starboard engine had to come out.
 
I found the invoices. One for removal, one for install. The shop had to remove the starboard engine, generator and prop so they could slide the shaft back. This is a V-Drive boat. Total cost of repair, with repairing the tank, was $7000. They also pumped out the fuel. These were estimates, not sure these are the final invoices as they are not stamped paid. I don't see a line item for the welding repair either.
 
Looks like I have a pin hold leak in my starboard tank. Found a little fuel dripping from under the tank. Going to be a big problem I would assume. Any ideas?
Have you been able to determine the location of the leak? Sea Ray didn't do us any favors gaining access to the tanks, but there is a possibility that your leak could be from a hose or fitting on the top of the tank and the drip you see is coming from there. Another thought is if it is a pinhole leak in the tank itself that you can locate, drain the tank and try some JB Weld. You might get lucky.
JBWeld.jpg
 
Cannot find the leak on parts of the tank which I have access to. I always go out with full tanks. I’m going to run the tank
down and see if the leak stops at some point. May give me an idea of where to look. Also will recheck all the fitting but saw nothing when I did a quick look.
 
Thanks Frank …uhh I’m disgusted. I was hopeful
For a sealant that could be placed in the tank somehow. tanks have always been full for storage and never have had any water intrusion.
Riptide did you have to remove the engine and floor?
As I have a sundancer not an express mine will be different, however, yes I had to remove engine, batteries, Vacu flush, prop, I would not repair the tank if you remove it. Way to much work to chance it on a 22 year old tank. I think I paid $2000 for a custom to my specs. Might have been less I could look it up. Could it be a vent hose Or fill clamp?
 
Are you sure it's the tank? I ask because the fuel primer pump on that side of the engine was leaking on mine and I thought it might be the tank again. After a fill up and cruising for about an hour I could smell diesel on that side of the engine compartment and see a damp bilge. Narrowed it down to the fuel primer pump, which I replaced this past weekend.
 
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The fuel is coming from the port side of the tank and traveling to the stern by the vac flush holding tank.
 

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