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Outdrive leaks, but holds pressure

P

ptudozer

Member
2006 Bravo3
I see a small amount of water at the bottom of lube reservoir, maybe a tablespoon.
Drained all gear lube, tested pressure. Had it at 10psi for 1hr. Added gear lube, took it out for about an hour trip. After a few days of sitting there's a line of water at the bottom of reservoir. And a couple drops of lube on floor emanating between inner prop and gear housing. How does it pass pressure test, but has small leak and allows water into the system. Any suggestions appreciated.
Ty
 
when pressure checking there is a specific way to do so. You give no indication on how you did it.

1. Pinch off oil line with taped jaws of vise vrips. Oil line is the one from transom to gimbal housing.

2. Drain out drive of gear oil.

3. Pressure check again to 15 psi.
A drive while in operation will produce 7-9 ish psi so 10 may not be enough to expose a leak. Also if you did not drain gear oil, then pressure test will not work.

If it holds for at least 2 minutes then retest using vacuum test. Should get around 6-8 in/hg vacuum and holding there.
 
kghost said:
when pressure checking there is a specific way to do so. You give no indication on how you did it.

1. Pinch off oil line with taped jaws of vise vrips. Oil line is the one from transom to gimbal housing.

2. Drain out drive of gear oil.

3. Pressure check again to 15 psi.
A drive while in operation will produce 7-9 ish psi so 10 may not be enough to expose a leak. Also if you did not drain gear oil, then pressure test will not work.

If it holds for at least 2 minutes then retest using vacuum test. Should get around 6-8 in/hg vacuum and holding there.
Click to expand...
I drained it, and pinched the hose right before the engine bay reservoir.
Guess will have to do another pressure and vacuum test.
In your experience, if oil is leaking behind the inner prop...just a few drops. Cold this be the main seal on the bearing carrier?
Ty, for the info and quick reply
 
The prop carrier has two seals for prop shaft. Back to back and visible one should have stainless steel cup which is a fishing line cutter.

Inside housing the carrier supports Eeveese gear. On prop side of reverse vear is a ~4" diameter oring that seals carrier to housing keeping gear lube in lower gear case.

Me personally 3 yrs ago, had a very slow leak allowing water in the gear lube. Not very much but enough so when drained after sitting, light green gear lube would drain first. It was that Oring and it failed under pressure test.
If it is that oring, two things happen, Oring gets brittle and housing gets corroded and scale grows on housing and oring and creates the leak. Mine is an Alpha drive but I believe the Bravo 3 carrier/oring and seals are the same basic design slightly different based on the size of the bravo 3 prop shaft .

Link to gear case and parts diagram. Items 45 (two seals at prop shaft, and Item 43 Oring sealing carrier to housing

 
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ptudozer said:
I drained it, and pinched the hose right before the engine bay reservoir.
Guess will have to do another pressure and vacuum test.
In your experience, if oil is leaking behind the inner prop...just a few drops. Cold this be the main seal on the bearing carrier?
Ty, for the info and quick reply
Click to expand...

Pinching oil line near reservoir would be effective if testing for gear oil leak between reservoir and bell housing which has a few connection where the line goes thru the transom
 
kghost said:
The prop carrier has two seals for prop shaft. Back to back and visible one should have stainless steel cup which is a fishing line cutter.

Inside housing the carrier supports Eeveese gear. On prop side of reverse vear is a ~4" diameter oring that seals carrier to housing keeping gear lube in lower gear case.

Me personally 3 yrs ago, had a very slow leak allowing water in the gear lube. Not very much but enough so when drained after sitting light geeen gear lube wiuld drain first. It was that Oring and it failed under pressure test.
If it is that oring, two things happen, Oring gets brittle and housing gets corroded and scale grows on housing and oring and creates the leak. Mine is an Alpha drive but I believe the Bravo 3 carrier/oring and seals are the same basic design.
Click to expand...
Ty, going to order both the O ring and 4" seal
It's going to be at least 7-10 days before I get to it. Will post results once I can get it all done. Have a great Labor Day weekend.
 
WHat 4 inch seal? The oring is about 4 inches in diameter. The seals are the diameter of the prop shaft
 
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