Boat leaks-at my wit's end.

Johnny Slalom

New Member
Jun 5, 2019
24
Madison, MS
Boat Info
99 Sea Ray Sundancer 270
Engines
454 Mercruiser w/Bravo III Drives
Bought a 99 Sundancer 270 in April and cannot find where it's taking on water in the bilge. Mechanics first said it was a boot-fixed that. Then the plug assembly was loose-fixed that. Then pulled the outdrive to repair transom seal. I've got to make a decision on what to do next. Any ideas on what else to check?? Any input would be greatly appreciated.
 
How fast does the water enter the bilge?

I used a small shop vac to vac out all the water in my bilge and climbed all over the place to witness where my water was entering. I have a steering pin that was gone bad in one of my transom assemblies which allows water to enter.

Does your outdrive have excessive play left and right?
 
Well with a single engine it shouldn't be that difficult to see where the water is coming in. Mirrors, light, go-pro.
The transom assembly has to come off to replace the seal. Did he do that ?

swivel pin seal
trim ram manifold gasket
goose neck water inlet on TA
trim puck wire seal
shift or u-joint bellows
Hole rotted through the TA
 
How fast does the water enter the bilge?

I used a small shop vac to vac out all the water in my bilge and climbed all over the place to witness where my water was entering. I have a steering pin that was gone bad in one of my transom assemblies which allows water to enter.

Does your outdrive have excessive play left and right?
It's pretty slow. I plan on asking the mechanic about the steering pin.
 
Well with a single engine it shouldn't be that difficult to see where the water is coming in. Mirrors, light, go-pro.
The transom assembly has to come off to replace the seal. Did he do that ?

swivel pin seal
trim ram manifold gasket
goose neck water inlet on TA
trim puck wire seal
shift or u-joint bellows
Hole rotted through the TA
 
Well with a single engine it shouldn't be that difficult to see where the water is coming in. Mirrors, light, go-pro.
The transom assembly has to come off to replace the seal. Did he do that ?

swivel pin seal
trim ram manifold gasket
goose neck water inlet on TA
trim puck wire seal
shift or u-joint bellows
Hole rotted through the TA
Yes, he did that. I will check with him on your other suggestions. Much appreciated.
 
Taking off the transom assembly (transom ring) also means pulling the engine.
Yes, he did that. I will check with him on your other suggestions. Much appreciated.

Was the engine pulled for the repair? I ask because removing the transom assembly (ring) requires pulling the engine. That’s also a common method of repairing a leaking steering pin.

A leaking steering pin is common due to Mercruiser using plain steel for the pin. It eventually corrodes and chews up the rubber seal. Checking for a leak is fairly easy. Find the steering linkage at the back of the engine. Follow it where it passes through the transom. It will be on center and above the bellows/ drive shaft area. Observe, or stick your finger in the space. If it’s wet the pin is leaking. It can leak without causing loose steering or play in the drive.
 
Taking off the transom assembly (transom ring) also means pulling the engine.


Was the engine pulled for the repair? I ask because removing the transom assembly (ring) requires pulling the engine. That’s also a common method of repairing a leaking steering pin.

A leaking steering pin is common due to Mercruiser using plain steel for the pin. It eventually corrodes and chews up the rubber seal. Checking for a leak is fairly easy. Find the steering linkage at the back of the engine. Follow it where it passes through the transom. It will be on center and above the bellows/ drive shaft area. Observe, or stick your finger in the space. If it’s wet the pin is leaking. It can leak without causing loose steering or play in the drive.
Yes, they pulled the engine, so hopefully that was checked. I will find out today. I'm just at a difficult place trying to decide if I can trust these guys' expertise or just cut my losses and go somewhere else. Or, should I expect to just have to live with water in the bilge. That doesn't sound like a good option. I've had bowriders all my life and this is my first experience with a cruiser.
 
Yes, they pulled the engine, so hopefully that was checked. I will find out today. I'm just at a difficult place trying to decide if I can trust these guys' expertise or just cut my losses and go somewhere else. Or, should I expect to just have to live with water in the bilge. That doesn't sound like a good option. I've had bowriders all my life and this is my first experience with a cruiser.

I'm sorry you're having trouble. I hope they checked out all that other stuff so you don't have to pull it again.

My father in law has a 1998 270 Sundancer and he was having water in the bilge for about 2 years. He was "just dealing with it" and it got to the point were he was bailing the boat most every day. There was a little oil in the bilge that the pumps sensed and prevented them from operating.

He was at the point of getting out of boating but we convinced him to get it fixed (by paying for it ourselves). His main issue was the transom assembly was corroded and leaking. The transom assembly itself is about $3000, so it's not a cheap fix. While the engine was out we had a number of other parts on it replaced to make it last, as it had salt water sloshing around in there. Pulleys, alternator, circulator pump, starter, oil pan, etc. It was a "make it right to last" kind of job. He had been extremely reluctant to do the job. But, now that it's done the boat is bone dry; I mean not a drop of water anywhere. He's thrilled with the outcome and it has renewed his joy in boating.

My point is, it's frustrating when your boat leaks and it's not good for it's longevity. If you can get a good mechanic to ID and fix the issue, I'm sure it will help your enjoyment. Oh, you might want to update your profile to show your location so folks here can better help.
 
I'm sorry you're having trouble. I hope they checked out all that other stuff so you don't have to pull it again.

My father in law has a 1998 270 Sundancer and he was having water in the bilge for about 2 years. He was "just dealing with it" and it got to the point were he was bailing the boat most every day. There was a little oil in the bilge that the pumps sensed and prevented them from operating.

He was at the point of getting out of boating but we convinced him to get it fixed (by paying for it ourselves). His main issue was the transom assembly was corroded and leaking. The transom assembly itself is about $3000, so it's not a cheap fix. While the engine was out we had a number of other parts on it replaced to make it last, as it had salt water sloshing around in there. Pulleys, alternator, circulator pump, starter, oil pan, etc. It was a "make it right to last" kind of job. He had been extremely reluctant to do the job. But, now that it's done the boat is bone dry; I mean not a drop of water anywhere. He's thrilled with the outcome and it has renewed his joy in boating.

My point is, it's frustrating when your boat leaks and it's not good for it's longevity. If you can get a good mechanic to ID and fix the issue, I'm sure it will help your enjoyment. Oh, you might want to update your profile to show your location so folks here can better help.
Man, your words of encouragement are very much appreciated. I'm not going to give up, but just been a tough day. I'm scheduled to meet with the mechanic soon to look at next step. Thanks again for your help and thanks to everybody else. This is an awesome forum. I will update my profile right away. Thanks again!!
 
I’m chasing similar issues on my 340. Don’t forget some leaks can come from rain and fresh water sources. I’ve been rebedding deck and hull fittings as well

so far I’ve found: my hot water heater was leaking, deck inspection hatches, bilge vent cover prop shaft seal, through hull transducer, ac seacock.

It’s getting better but I keep finding new stuff
 
The best idea I've heard to to totally dry the bilge and get in there and find the leak. So many areas are of potential. Leaving it to a herd, they will not sit in it and wait. I would dry it. Sit in the water and watch everywhere for a few hours. Next I would have someone use a hose and start spraying different sections one at a time.
 
Johnny Slalom,

If the mechanic pulled the engine, did he go ahead and disassemble the gimbal/transom assembly and replace the steering pin seal? I see no other reason to pull the engine when looking for a small water leak. I hope he did since I would bet money on a boat that age needing a steering pin seal replacement.

Unlikely, but the Y-Pipe May be corroded and leaking near the connection to the transom assembly. Surely that would have been handled on an engine pull.

I have a small water leak where the exhaust riser meets the rubber connector to the Y-Pipe. I plan to handle that this winter.

There are so many possible leaks in our older boats.

Like playing Whack-A-Mole.
 
I have heard good reviews of the JR Marine procedure. I would be doing that if my nearly 20 year old transom assemblies weren’t corroded badly.
I just bought the boat and transom assembly replacement was figured into the purchase price.
My challenge now is determining a long-term rust-corrosion prevention strategy.
 
I just went through this. Got a shop vac and vacuumed up every drop of water. Even ran for another 5 min just to dry out the area. Then get yourself a borroscope camera. I got a $30 depstech thing on Amazon that works perfectly for this. Find a drop somewhere and you'll narrow it down.

Once I found the drop location that was dripping every ten seconds, I folded up a paper towel and dryed up the area under the steering arm on the transom assembly. Then took a second dry paper towel and put it again under the steering arm. I watched my leak slowly stop for two or three minutes. Then it started again, and sure enough the paper towel was saturated indicating it was leaking.

I think you can even do the paper towel trick without watching or finding the drip. I will say that the water runs down the transom assy on the inside and is very deceiving to figure out where it is coming from. I also was surprised that such a small leak causes a gallon or two of water a day.

So now I am unfortunately pulling engines and hoping I don't need two new transom assy. It is ridiculous that Mercury doesn't use stainless. They should have upgraded all designs to SS at their cost knowing how costly it is because of this design problem. Imo, it's the biggest problem on mercruiser, followed by costly disposable manifolds.

Anyways I hope it's not the steering pin! But from what I've seen, they all leak in salt. Good luck.
 
Did steering pins a season and a half ago using the jrmarine kit. Went pretty good, did have an issue getting one side to seal up, but after 3rd try it did. Been doing well so far. Wasn't really hard to do, only had to be patient - not rush it and no cutting corners.
Replaced pins with the stainless ones. On my last boat (Maxum) did transom assembly for same leak problem. It was too corroded for the kit. Do not do the Mercury kit that involves drilling holes in the sides of the top of the transom assembly - have heard nothing but bad results from that method. Best of luck.
 

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