Water leaking into the bilge at rear of the engine

E

emckissack@hotmail.com

Member
May 21, 2016
134
Pensacola
Boat Info
240 Sundancer 2007
Engines
5.0 Bravo 3
So, I have been chasing down a water leak into my bilge for some time. Well yesterday, I decided to look the engine over while she was in the water and low and behold, I found a drip coming from the center of the rear section of the engine approx 2-3 inches from the transom. I took a video but can't pinpoint where the drip is coming from and do not know what is in that area that could possibly leak. Any advice/ assistance is appreciated. Thanks for looking.
 
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3 inches from the transom should not be the transom . If dripping from the rear housing area only thing behind there are a cam plug and core plugs.
Other than that a crack from poor winterizing.
Other area may be the power steering cooler if mounted high aft , loose hole clamp.
Outside chance the exaust Y pipe has a corroded hole in it

pull it and run it on muffs, cold water from the hull drain =raw water side leak
warm water from the hull drain- exaust Y pipe leak
 
Good thought. I don't have the boat handy at the moment but when I run it on muffs, I don't recall seeing any water coming out of the drain hole. I'll have to check it out next weekend though. Thanks.
 
If I had to put money on this I would say it's the bellows for the CV joints on your outdrive that is leaking. Either a hole in it or disconnected at one of the hose clamp. If trailered or kept in a boatel or lift, Raise outdrive up to highest position and look at the largest bellow under there to see for damage. The leak should only occur when in the water regardless of the engine running or not.
 
Could also be the Shift Cable Bellows. If water gets past the bellows it can run back on the shift cable and trip at the lowest point. I had this happen to me. Took the better part of a couple of months to track it down.
 
Does it get worse when you tilt the drive? My vote is shift cable bellows. I would say it’s time to pull the drive and have a good look at the bellows. Usually when one goes - the first is usually shift - then the others aren’t far behind. Do the bellows, shift cable and trim sender/limit at the same time.
 
Swivel shaft seal inside gimbal housing is also a possible culprit. Not a fun replacement job, did it on my 290DA bravo drive.
 
Quint4 said:
Swivel shaft seal inside gimbal housing is also a possible culprit. Not a fun replacement job, did it on my 290DA bravo drive.
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Yeah, that's the other possibility, hopefully not, that's definitely a bigger job. If the steering pin is leaking, the leak is from the top of the transom assembly, it should be easy to find evidence of the leak. It will be around where the steering arm goes through the transom assembly. If it's the shift bellows, the leak will be at the bottom of the assembly where the shift cable comes through.
 
Sounds like the steering pin. They are an issue on the B3 drives.
 
The Mercruiser repair process involves pulling the motor and transom assembly to get to the steering pin. There are aftermarket repair kits (JR Marine is one) that cuts an access hole in the top of the transom assembly from the outside to give access to replace the steering pin. They provide a stainless steel plate to cover the hole. Google Mercruiser steering pin, there are lots of articles and videos on the process. I've never done it myself, but from what I have seen, I would go the JR Marine route unless I had some other reason to pull the motor.
 
......thats what I said...swivel shaft seal.
 
emckissack@hotmail.com said:
Let’s hope it’s not the swivel shaft seal then.
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The repair isn't that big a deal, I've done a couple.
Just make damn sure that's your leak. Get in there with a light and a mirror and pinpoint the area.
I assume you have made sure it's not your bellows ?
 
scoflaw said:
The repair isn't that big a deal, I've done a couple.
Just make damn sure that's your leak. Get in there with a light and a mirror and pinpoint the area.
I assume you have made sure it's not your bellows ?
Click to expand...
I have not really been able to nail down where the leak is coming from. I took the video this past weekend and now have the boat on the trailer in storage. If the weather is good this weekend, I will be able to do some in and out of water testing and more videoing with the go pro to try to pin point the leak, I will keep this thread updated with what I find.
 
You can / should inspect the bellows while it is on the trailer. If the leak is coming from either the shift or u-joint bellows it will be obvious.
 
Pay more attention to the transom assembly, if the top pocket where the steering shaft is, has a puddle in it, it's the swivel shaft seal. It can also leak from the gooseneck water outlet
 
If you run it on land and do not see any water dripping then suspect a main bellow. shift cable bellow, water inlet bushing, loose transom.
If you see water dripping on land then suspect Y pipe leakage although it would be further back toward the transom and not under the rear housing.
Under the rear housing are core plugs that could be rusting(steel core plugs) or a crack from freeze damage.
 
So I ran it this weekend on muffs only and did not see any indication of a leak while letting it run. I guess I will have to check it out the next time I have it on the water.
 
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