Locating a Water Leak


The following is a summary of a discussion on yahoo.groups on trying to track down a water leak.

From Bill


My Brewer44 with a center board is taking on enough salt water to fill the bilge

every 6 hours.The usual suspects: through hulls, sea chest, rudder, stuffing box,

etc., don't show leakage and even after pumping out we can't see flows, ripples

or dripping into the bilge. We looked at the area under the dinette that houses

the lead to the center board and saw no leaks.


I hope to resolve this without hauling.


Any ideas?



From Greg on My Destiny


Strategically placed paper towels can help locate leaks.....

Sounds like you've eliminated the water tanks. Have you inspected ALL



Can your holding tank be filled upon a particular arrangement of valves? When I

bought my boat the PO had installed a modification that when set one way, allowed water to fill the holding tank. I caught it in time but it could have created a

similar situation and several others have found similar faulty arrangements.


Do you have a Dynaplate or similar that has corroded away and leaking at the

thru-bolts? What about depth and speed sensors? Do you have a refer/freezer

keel cooler?


.....And you're SURE it's all salt. Your water tank levels are unchanged?

I'll go back to the paper towels helping track the source down. Good luck.



From Lee on Head Out


Experienced a similar problem on my Brewer44 (Hull # 268) recently. It

turns out the check valve in-line with the manual bilge pump outlet,

which connects to the port above-the-water through hull, had failed

(corrosion had destroyed the flapper valve, with no outward signs at all).


In my case, the sea water cooled refrigeration system would cycle and

back fill through the defective check valve through the manual bilge

pump into the bilge - no drips, flows or ripples were evident unless you

pulled the manual bilge pump hose out of the bilge and watched it closely.


Definitely was a perplexing problem.... hope my personal experience

points you in a possible direction.



From Peter


You also could have a siphon from an overboard where the anti-siphon valve is

not working. Had an experience south of Bermuda when the floor boards started to

float... On a port tack bilge pump siphoned...



From Dave


I have a check valve on my bilge discharge just before the discharge gets to the manual pump (high point in the circuit).  The discharge hose is shared between the automatic pump and the manual pump.  The check valve keeps the water from backing into the bilge.



From Julia


I'm new on the list and don't currently own a Brewer, so I'm not familiar with

the plumbing or access locations, but... 


1) Taste that it is salt water vs a leak in the water tank or purification


2) can you shut off all the sea cocks (i.e. isolate leaks from hoses, secondary

connections, engine water filters, all bilge pumps, toilets, etc.).

3) can you put paper towel sheets down around the rudder post, through-bolts,

and every thru hull entrance in the boat including the instruments (knot meter,

depth meter, water temp, etc.) [This is a plumbers trick I use at my house after

installing new plumbing to insure that it's not leak, except in the house I put

a bowl or pan under the paper towel to catch the water if it is leaking.]

4) can you put paper towel down at various locations in the boat (i.e. anchor

locker, under the v-berth, mid section locations, in the engine compartment and

under the aft cabin to start isolating the potential area of the leak. If the

Brewer has a pan or liner, this might be more difficult because the leak could

be running from a different locations like water dripping down a joist/beam in a

house before eventually dripping through the ceiling several feet away).

5) Check anti-siphon/check valves

6) Last resort options (I hope you are in a warm water area):

a) plug all thru hulls from the outside or in

b) this includes all instruments (knot meter, depth meter, water temp, etc.)

c) if this stops the leak, then start removing the plugs one at a time with

several hours between each plug to identify which thru hull is leading to the


d) if this does not stop the leak, then you need to dive under and look for

hull damage.



From Tom


You have already gotten a lot of ideas on this but here's another.  This year when I launched by Brewer 12.8, I found my bilge filling with water.  I traced the problem to a crack in the cover plate for the Forespar sea water intake strainer.  Took me two days to locate a replacement but that's another story.



From John on Menehune


Very interesting. Our Whitby came equipped with a Forespar (plastic) sea

strainer.....and within the first two years, I had to replace it twice....it had

cracked near the top; and, yes, the leaks were very difficult to locate because

of the clear plastic....but the paper towel trick helped me locate the culprit.


No more plastic here! Now have a bronze Groco......



From Bill


Thanks to you all, who gave helpful suggestions about finding my filling bilge problem.

Lee Davis hit the nail on the head. It was the manual bilge outlet siphoning water into the bilge and that explains why there was no visible leak.


What a great resource this forum is for us Brewer owners.


From Bill


At our last correspondence I thought that the problem was resolved and that the water was a siphoning issue with the manual pump. I had simply and temporarily stopped the flow, it appears, by cleaning the bilge with a mop, whose lint formed a temporary gasket around the real problem. 

A couple of days later the flow restarted and since the water was clearer, a slight ripple appeared, but still was not showing the source. Finally, I hauled the boat and the problem was apparent. My Brewer is a center board model and sometime in it's history rubber bumpers were installed to cushion the side movement of the board. The idiot (and I mean that literally) who did the installation screwed lag bolts all the way through the hull penetrating the bottom of the bilge. One of these was rusty and falling out. The other 5 bolts would probably have done the same over time. The bolts were removed, the holes filled, and the bumpers properly installed. 

I assume that my experience is an anomaly, but if any of you have a center board, please check for problems with installation of the bumpers