Water in Bilge After Running Boat

M

maxse

Member
Apr 16, 2017
108
New York, NY
Boat Info
260 Sundancer 2007
Engines
Single Mercury Stern Drive 300HP Bravo III
After running the boat I’m getting a few gallons of water in the bilge. It only happens after running the boat and is not happening at the slip.

When idling at the slip I do not see any visible leaks.

I do see some staining under the power steering pump and this would make sense since the swim platform is above the water line and it’s only making contact when planing.

Has anyone run into this? Can I just unscrew and apply 4200/5200 or is this a potential bigger repair?
4AD9DC16-2CB0-4878-AA70-7DF0CF1FCC5C.jpeg
 
Espos4 said:
That’s your trim pump and the staining is from the bracket rotting out.
Click to expand...

Got it, so it’s not likely this is the source of my leak?

I see some rusting and moisture at the top of the outdrive assembly pictured below maybe this is the issue?
B8849C29-48E3-4B57-9A9D-8DE6059A38F6.jpeg
 
If the seal and bushing was leaking you would see the drip. Seeing the rust on the trim pump suspect leaking rub rail allowing water to enter that way.You can test with a strong stream from a hose
 
I found the culprit...I guess this must have been damaged when the boat was launched and it’s enough to allow water in when planing.

1FD079B8-D942-4AE2-8D48-8BD1FDAB3F42.jpeg
 
That does seem like a lot of water for that type of opening since it would only be submerged for brief periods.

Is it possible you could have a leak in you cooling water supply system while under pressure, like engine running under a load?
 
maxse said:
Got it, so it’s not likely this is the source of my leak?

I see some rusting and moisture at the top of the outdrive assembly pictured below maybe this is the issue?
View attachment 88761
Click to expand...
Looks like a lot of rust on your steering arm coming through the OD. My thoughts would be steering pin(s) seal is leaking. Common on Br 3 drives. Expensive repair/replacement.
 
Korkie said:
Looks like a lot of rust on your steering arm coming through the OD. My thoughts would be steering pin(s) seal is leaking. Common on Br 3 drives. Expensive repair/replacement.
Click to expand...
I had the same thought on the source.
 
DWABoat said:
That does seem like a lot of water for that type of opening since it would only be submerged for brief periods.

Is it possible you could have a leak in you cooling water supply system while under pressure, like engine running under a load?
Click to expand...
This happened to me and it wasn't until the entire hose came loose until I realized it. A hose clamp had rusted and broke on a hose at the bottom side of the engine. When the hose came loose water poured into the bilge and the check engine indicator came on. As soon as I shut down the engine the water stopped and I was able to fix the problem. There were a few indicators that made sense after the fact. 1) Water in the bilge after running. 2) The water pressure on that particular engine was always showing lower that the other. This makes sense (i think) because some of the water was leaking out and the pressure was lower as a result. I would suggest checking to make sure all the hoses are secure and not leaking. Easier said than done..but worth looking at them.
 
I was surprised to see that amount of water coming in from that small hole...as soon as I used 4200 to seal it up...no more water in the bilge after running.

I will have to clean up that rust from trim bracket in the fall and replace it with a stainless one...change out the 4200 for 5200 a bit neater than I was able to do while in the water.

I will also keep an eye on steering pin seal and dry that out completely to ensure no water is coming in.
 
I have the exact same problem on my sundancer 260.....i show no signs of leaks...checked EVERY hose clamps, tried taping off all discharge ports, placed paper under the engine while running in the slip....absolutely makes no sense....your guess is better than mine, transducer, water tank, ac unit, water storage.........water temp is always same as bay water...not engine tempature...help is needed
 
It turned out to be the transom assembly. Apparently it is somewhat common after some time. Repair was around $5k with labor and parts. They have to pull the engine/drive.
 
I just went through this in my 260. My bond flange was leaking and I wound up resealing my whole hull/deck joint. It’s in my thread
 
You must log in or register to reply here.

Forum statistics

Threads
113,121
Messages
1,426,614
Members
61,037
Latest member
wojozobl
Back
Top