Elusive leak in fresh water system

[Yeoman_24]

My Moody 30 has had a leak in the fresh water system that I just can’t track down. I have 2 water tanks. A high one across the transom and a low one under the quarter berth.

I slowly coming to the conclusion it is the lower one which which may be leaking somewhere but the boat interior appears to have been built around the tank (although there is a siliconed down hatch along the quarter berth).

Has anyone else experienced this problem or agree with my diagnosis of a leaky 45 year old water tank?

Its not a rain water leak as I have definitely eliminated that.

 

[harvey38]

Assuming it is the pipework and not the tank itself, I would shut off both tanks, thoroughly dry the wet area and see if moisture comes back, if not, open one tank at a time and see what conclusions you can draw. Obviously if the tanks themselves are leaking then isolating them will provide little help.

 

[AndrewB]

Do you have polyethylene tanks like on my Moody? If so, its hard to see how they would ever leak unless actively punctured. Suspect all the pipework connectors first. I spent a long time tracking down a leak until realising it came from where a sensor had been fitted to the tank: usually it seemed dry but the fitting seeped when the tank was filled and became very slightly distorted.

Are you quite sure it isn't rainwater? On a 45 year old yacht, the caulking around all deck fittings will have perished, and this is a very likely source of leaks.

 

[Spirit (of Glenans)]

Blue paper towel, strategically placed, (if you can gain access!), helps in showing up the origin of leaks, as fluids make it darken.
It also occurred to me, FWIW, you could try dosing the suspect tank with edible vegetable dye.

 

[stuartwineberg]

As always try the moody owners tech forum, you are unlikely to be the first facing the issue

 

[yoda]

Chec

My Moody 30 has had a leak in the fresh water system that I just can’t track down. I have 2 water tanks. A high one across the transom and a low one under the quarter berth.

I slowly coming to the conclusion it is the lower one which which may be leaking somewhere but the boat interior appears to have been built around the tank (although there is a siliconed down hatch along the quarter berth).

Has anyone else experienced this problem or agree with my diagnosis of a leaky 45 year old water tank?

Its not a rain water leak as I have definitely eliminated that.

Check around the pump connections, I found mine were slightly stressed and leaked slightly, took a fair while to identify but a small container under the connections proved it.
yoda

 

[Donheist]

My Moody 30 has had a leak in the fresh water system that I just can’t track down. I have 2 water tanks. A high one across the transom and a low one under the quarter berth.

I slowly coming to the conclusion it is the lower one which which may be leaking somewhere but the boat interior appears to have been built around the tank (although there is a siliconed down hatch along the quarter berth).

Has anyone else experienced this problem or agree with my diagnosis of a leaky 45 year old water tank?

Its not a rain water leak as I have definitely eliminated that.

You know there’s a leak because of water in the bilge or because the pump keeps firing? We turned our boat upside down before someone suggested I check the cockpit shower hose. Sure enough it was dribbling…just a thought.