Fuel Tank Replacement 400DA

[fwebster]

The water most likely came in the fuel fill, and the corrosion started inside the tank………not from the outside in. The way this tank mounts, it is up on a shelf outside the stringer and water won't stay there, it will run off. The moisture was introduced in the fuel or from rain/wash water because the o-ring on the deck plate is cracked or someone left the deck plate loose.

Before you buy this boat based on a $10K estimated cost, you need to have someone bore scope the other tank to check for water/corrosion…….and whomever you choose needs to have some experience at this, not your brother in-law- with his Harbor Freight scope. Corrosion inside a partially filled fuel tank is tricky to spot if you have never seen it before. If you miss this and the other tank leaks next month/year, you are looking at a $10K do-over.

 

[stephens013]

Two years ago a 450da in my area had leaking tanks; guy had to lift both motors and them have tanks manufastured.

 

[ttmott]

These tanks are installed before the top of the boat is mated. There are tabs and rubber cushions that hold the tank down along the top. On the starboard tank, which has the best access, you can get to these tabs from the access plate in the aft cabin book shelf.
No doubt the aft head VG, generator, starboard engine exhaust, deck support rail and all of the interfering wiring hand hoses will have to be removed (as a minimum). If you are in that deep might as well replace all of the VG and generator hoses, do the generator valve service, accessory belt, and clean / paint the vacated area. Also while you are that far in take a close look at the water heater; if it's the original might as well replace that also....

 

[Sundancer_340]

Thanks for the photos and ideas. The leak was discovered in 2011, so hopefully port is good. Port is 100% full, so I imagine difficult to scope. Stephens13, do you recall what it set you back and the cause?

 

[douglee25]

Sorry I can't help anymore with this thread.

I moved on after I looked into the work that it would require to replace the tanks on that boat.

Do