Need some advice please - 1987 Sea Ray 390 freshwater tank leaking

[tkennedy]

Yesterday I topped off the freshwater tank. Bilge pumps kicked on. Tank eventually filled up but 30 minutes later was empty.

Tank is stainless steel. What should I check:

1. Fill line? If so, how to I gain access to it in salon
2. Freshwater tank leaking? Can remove one deck hatch in salon and see forward end of freshwater tank. Will I have to cut floor in salon and replace tank?

Any advice would be GREATLY appreciated!

 

[Mike Blake]

One of the lines have a hole in it?

 

[fwebster]

You access the fittings on the water tank from under the cabin entry steps; however, if the tank is emptying itself into the bilge, then the leak is low on the tank and you probably have a hole corroded thru the bottom. I think you will find that the tank is aluminum, unless someone has already replaced it. Our 390 was an '88 and as I recall, you could remove the tank without tearing up the salon floor, but the tank has to be taken loose and slid forward to the hatch opening, then lifted out, and it isn't a particularly easy or fun job.

 

[tkennedy]

One of the lines have a hole in it?

I don't think so. Water pump (freshwater) was on but in checking lines to/from it I saw no leakage (area was dry). It seems maybe the tank itself leaked and water went through limber hold into engine room where bilges pumped it out.

If I need to replace tank should I use plastic or stainless steel? Also, where is the best place to purchase one online?

Thanks!

 

[Deuceornothing]

If its an aluminum tank like frank says it might be have the crack welded and I would pressure test it while its out to see it you have any other weak spots to patch.

 

[fwebster]

I wouldn't try to fix an aluminum tank with a corrosion problem. Your chances on a replacement are going to be limited due to the width constraint between the stringers and the height available below the salon floor. One approach to consider is to email Sea Ray customer service and ask for help with the OEM tank specs and vendor. On a boat this old, they won't force you to go thru a dealer and you might be able to get the OEM vendor to build a replacement for you.

 

[IanBat]

I don't think so. Water pump (freshwater) was on but in checking lines to/from it I saw no leakage (area was dry). It seems maybe the tank itself leaked and water went through limber hold into engine room where bilges pumped it out.

If I need to replace tank should I use plastic or stainless steel? Also, where is the best place to purchase one online?

Thanks!

Turn the water pump off, refill the tank, , and see if the bilge pump cuts in, then trace to see where it is leaking.

If the bilge pump doesn't cut in, tank doesn't leak, then turn the freshwater pump on and see if the bilge pump cuts in, if so then follow the flow from the bilge and inspect water lines.

To empty the tank in 30 minutes there should be a substantial leak, so shouldn't be too hard to find.

My last one was the transom shower.


Sent from my iPad using Tapatalk HD

 

[390x]

I replaced mine 3 years ago with a plastic one. The factory ones all leak as they are a bad design. Aluminum sitting directly on fiberglass will definitely corrode and develop leaks. Then once they leak, they soak the foam/plywood under the tank and ruin that too. They can also take the stringers with if you don't catch it soon enough. You have to rip the floor up above the tank and cut an s-shaped curve back by the stairs. Once you have done that, it's easy to just lift the tank out. You have to give that floor and the stringers some good soundings with a hammer and decide if they're saturated, which they probably are. I had to rip all of that out and replace it. My new tank came from www.tank-depot.com I believe it was like 88 gallons or something like that. I didn't see the need to pay the money to get a custom one made to match the original exactly. Have fun!