Volvo Penta 280 - water in outdrive oil

jb1527

Cadet
Joined
Aug 22, 2017
Messages
6
Removed the outdrive and started disassembling to replace the broken suspension yoke. When I pulled the plug from the lower unit, it ran pretty clean looking water - maybe 16oz. or so - before the oil started flowing.

I noticed that the seal on the aft side of the upper gear housing was oozing oil slowly while the outdrive sat in the rack (before I pulled the plug). Is that a likely culprit? Any better suggestions?
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Jul 23, 2011
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47,297
if the u-joint shaft is rusty, most likely the culprit is the input shaft seal. you will need to replace the shaft, input seal, and the sealing washer. and prior to putting back in service, perform both a pressure test and vacuum test per the manual.
 

PiratePast40

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Mar 21, 2009
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Until you perform the pressure and vacuum tests, you won't know what is causing the leak. Not sure where on the upper housing you have the present leak, but you may want to replace those/that seal first so you can do a complete test. The shift shoe and top plate seals are easy and inexpensive to change out so may want to start there. Like Scott mentioned above, it could get into more extensive repairs if that front seal is leaking.
 

QBhoy

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Mar 10, 2016
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8,286
Famous for it....along with the 290 leg. If you have the standard black rubber "o" ring seals that VP issue for the drain and vent plugs....ditch them for the Merc fibre washers and run a smeared finger full of silicone over each of them after each oil change.
This will sort out the problem....outwith any major other reasons.
 

jb1527

Cadet
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Aug 22, 2017
Messages
6
Thanks everyone. I *think* I've got the leak stopped. No way to know which of the handful of things was the culprit at this point.
 

PiratePast40

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Mar 21, 2009
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Thanks everyone. I *think* I've got the leak stopped. No way to know which of the handful of things was the culprit at this point.
I'm amazed at the number of people that talk about having leaks and then never run the pressure or vacuum tests that are in the manual.
 

jeffnick

Senior Chief Petty Officer
Joined
May 24, 2004
Messages
695
I'm amazed at the number of people that talk about having leaks and then never run the pressure or vacuum tests that are in the manual.

Can you supply a source and part numbers for everything needed to do the pressure/vacuum tests?
 

PiratePast40

Lieutenant Commander
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Mar 21, 2009
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Here's a link to the one I use:
You can also make your own if you want. The procedure is in the manual. I'll upload that particular page.

I like to keep extra drain and fill o-rings and gaskets on hand. You can get those part numbers and order from the iboats shopping section. Can't stress how important the testing is when you are dealing with unknowns. If you don't test, you are really just guessing about which components are leaking. Would hate to button things back up only to find you still had leaks.
 

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