Hints and Tips



Lift keel water pressure leak issue

Solution to avoid the problem when drying out in mud


Based on original posts from the Jeanneau Owners Forum


Several Jeanneau lift keel models, for example Sun 2000, SO35 and SO379 have found problems when repeatedly drying out on mud, when seawater may be ejected from the inspection plate. The problem does not seem to occur if beaching on sand.

This is due to the mud being forced up then blocking both the lower aperture of the keelbox and critically the drain seacock. Hydraulic pressure then pressurises the keel box and the trapped water can then be forced past the inspection plate and into the bilge. If the boat is left for long periods on a drying berth then considerable quantities of water over time can build up. Jim Dew solved this problem by fitting a seacock above the waterline and then diverting the pressure relief overflow pipe.


But an alternative helpfully fully described below by Yakomo shows how the overflow pipe may be diverted to an existing seacock above the waterline, perhaps in the head or galley:


Our SO35 has a crank mechanism to move the lift keel up and down. As far as I know the same mechanism is used in the SO389.

Above the inspection hatch there is an overflow with a hose which is supposed to drain off water when it dries up. Unfortunately Jeanneau directs the overflow to an outboard valve which is located in the bottom of the ship directly next to the centreboard box.



If you fall dry on sand everything seems to be okay. But if you fall dry in soft mud a lot of mud is pressed into the centreboard box and at the same time the valve is blocked by the mud. The water is pressed upwards to the crank mechanism. The inspection hatch cannot hold this pressure, but even if it could, the water would escape through the bearing for the crank .


Jim Dew has already described the solution in: Hints and Tips Sun Odyssey 35 Swing/Lift Keel He installed a new valve.   I didn't want to install a new valve, so I looked for another solution. My first try was to use the hose of the bilge pump via a 2-way valve.


Unfortunately this didn't work, because the hose of the bilge pump comes from the bilge goes up behind the bank until above the waterline, runs from there to the aft and goes outboard via a gooseneck. The hose runs higher than the highest point of the crankcase/inspection hatch. The static pressure becomes too high and a lot of water continued to enter the boat.


On the SO35 is in the wet room one valve for the wash basin and one valve for the shower just above the waterline. I thought about using the shower valve to drain the centerboard. For this the shower water is led via a 2-way valve to the wash basin valve. One difficulty was to find a way for the hose below the waterline to the old shower valve. Fortunately the frames have holes for the bilge water and after a little bit of poking I could use them. It was pretty difficult to come to the wet room but in the end it worked.


Today we have a dry bilge.

For us this is it important because we lie in a harbour with soft mud which is dry 2 times a day.




Based on original posts from the Jeanneau Owners Forum