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Major Leak Question

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SolSimple

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I just bought a 97, 20' proline with a 6 cyl inboard outboard Volvo Penta, it was not used much for the past 10 years but the engine was well maintained. I took it out the first three days and it worked famously, then I launched it again about two weeks later and it was seriously taking on water to the point the bilge came on by itself and it could not keep up. Knowing it was not the plug I pulled it out and the plug was in place and well tightened.

The lower bellow was showing signs of rot in the valleys and this is the only thing I could come up with but is this a reasonable cause for this much water? I have not owned a boat in 20 years so would like some advice before I start tearing things apart.

In addition this was also salt water so any other advice other than rinsing out the inside of the hull would be appreciated.

Thanks for any help you can lend. Don
 
It's possible that the drive shaft bellows have failed..... especailly if it has not been replaced recently, and even more likely if the previous owner stored the boat with the drive trimmed UP!

Salt water (from a leak here) will ruin the gimbal bearing (if this is an SX style drive) or the PDS bearing (if this is one of the last AQ series drives).



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RicardoMarine said:
It's possible that the drive shaft bellows have failed..... especailly if it has not been replaced recently, and even more likely if the previous owner stored the boat with the drive trimmed UP!

Salt water (from a leak here) will ruin the gimbal bearing (if this is an SX style drive) or the PDS bearing (if this is one of the last AQ series drives).



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Would this cause this much water to leak into the hull though? Thanks
 
bondo said:
Ayuh,.... My Guess is,... yer transom is Rotten, 'n allowin' the water in,...
Click to expand...
There is no indication of rot though. The hull is in extremely good shape for it's age, even the engine compartment is almost spotless. I don't understand how an exhaust or drive bellow leak could penetrate to the hull at such a rate. Although I have limited experience with the I/B O/B setup.
 
In 1997, this could be either the last of the AQ series drives, or it could be one of the gimbal system drives.
Being a six-cylinder, I would assume that this is the GM 4.3 L V6.

More information would certainly be helpful!

Which type of engine cooling?
Raw Water cooled, or Closed System cooled?

How was the engine and exhaust system last winterized?

When was the most recent driveshaft Bellows replacement?

Is the inner-most end of the shift cable "sheathe" well above the waterline?



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RicardoMarine said:
In 1997, this could be either the last of the AQ series drives, or it could be one of the gimbal system drives.
Being a six-cylinder, I would assume that this is the GM 4.3 L V6.

More information would certainly be helpful!

Which type of engine cooling?
Raw Water cooled, or Closed System cooled?

How was the engine and exhaust system last winterized?

When was the most recent driveshaft Bellows replacement?

Is the inner-most end of the shift cable "sheathe" well above the waterline?



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Click to expand...

It is the GM V6, Raw Water cooled, no survey but I bought it from a buddy of mine who runs dive boats and fishing boats. He is insatiable about his maintenance and everything is very clean with no evidence of dirt or salt buildup. I have not doubt that the drive shaft bellow has failed due to age and lack of use and needs replaced and I will do this but my question really is;

Will a failed bellow allow that much water to leak directly into the hull as described in the original post?
 
Your scenario offers too many variables given our limited info!

1.... How large and what is the capacity of your bilge pump?
A small pump may not keep up with a mild leak.

2.... Is this an AQ series drive, or a Gimbal system drive?
IOW, we need to know what path this water may be taking.

A short, simple, but non-complete answer to your question is ........ Yes!
Water can enter the engine bay via a breached drive shaft bellows!


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With the boat on the trailer, back it down a ramp and fire it up. Look for the leak. If the exhaust pipe is rotted thru the exhaust noise will be loud in the bilge.
 
RicardoMarine said:
Your scenario offers too many variables given our limited info!

1.... How large and what is the capacity of your bilge pump?
A small pump may not keep up with a mild leak.

2.... Is this an AQ series drive, or a Gimbal system drive?
IOW, we need to know what path this water may be taking.

A short, simple, but non-complete answer to your question is ........ Yes!
Water can enter the engine bay via a breached drive shaft bellows!


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I do not believe it is a gimble drive but sorry not sure. The bilge was pushing an estimated 12-15gpm, lots of water. One week the boat was water tight and bone dry after three days of boating and a couple of weeks later it was sucking in water at an incredible rate but I could not see where from inside the engine compartment. The trim was never down so I think having it up and the bellow stretched along with age of the bellow it just picked that day to fail. I'm going to go ahead and replace it and drop it back in the water I just didn't want to waste my time or not accurately attack the problem.
thanks, Don
 
Don, can you please post a few photos of your engine and drive for us?

This forum, and many others, are here so that we can help people like yourself...... but you must participate and at least meet us half way!
Otherwise, we are all spinning our wheels and wasting time here!


Have you followed the shift cable down and found where it enters the shift cable "sheathe"?
Is the interior end of the sheathe above the water line?

As for replacing the bellows only..... you need to know that water entering either a PDS bearing (AQ series drive), or a Gimbal Bearing (SX gimbal system drive) will cause eventual bearing failure.


Which drive here looks like yours?

This first one is an SX Gimbal system drive.
http://m.ebay.com/itm/141163973917

This one is an AQ style drive....... but in the Duo Prop version.
http://m.ebay.com/itm/261388758315



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This is a picture of a Volvo SX Exhaust pipe. Just like the one you have. This one is a 2004. The black is carbon from the exhaust blowing on the transom. According to the customer, it was fine in the morning and started leaking in the afternoon. This would have sunk the boat if the bilge pump failed. On your boat this pipe, the shift bellows and the trim sender are the main sizable possible water leaks. The drive bellows leaking will not be enough water to run the pump constantly. The exhaust bellows will not leak water into the bilge either.





DSCN2161crop2.jpg
 
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Chris, since we do not yet know what boat make this is, here is why I mentioned the possibility of either drive style!

Volvo Penta continued the AQ series drives (right alongside of the gimbal system drives) through 1996 in the gasoline version, and into early 2000 for the diesels.

I agree.... a leak from failed bellows would be minimal..... but again, we do not know what size bilge pump his boat is fitted with.


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RicardoMarine said:
Chris, since we do not yet know what boat make this is, here is why I mentioned the possibility of either drive style!

Volvo Penta continued the AQ series drives (right alongside of the gimbal system drives) through 1996 in the gasoline version, and into early 2000 for the diesels.

I agree.... a leak from failed bellows would be minimal..... but again, we do not know what size bilge pump his boat is fitted with.


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Click to expand...

"I just bought a 97, 20' proline with a 6 cyl inboard outboard Volvo Penta,"

Doubtful it is a diesel or an AQ series.
 
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