Slow leak from top cap plate of Bravo 1

[etk]

Hello All,

I have a 2004 single Bravo 1 drive serial number OM series and 5.7 FI magnum motor. Owned for 2 seasons. I noticed an oil film at marina a few months ago appearing near top plate cap of drive, so tilted drive about 2/3rd's way and then didn't notice the oil film appearing on water next time I went out.

Pulled boat end of season and got the alarm beep because drive reservoir level was low, but not totally empty. At home on trailer a week later, I tipped down the drive and noticed a small amount of oil seeping from the port side of top plate cap, almost at the rear of the cap. I removed the drain plug behind the prop without warming up the motor, as I wanted to see if any water settled at the bottom of drive. I got about 4 to 6 oz water before the drive oil came out. I removed the upper vent plug soon after. Oil looked good other than the initial water (no pieces of metal on the plug magnet). Boat was used only 7 times this summer and only went through 2 tanks of fuel. I refilled through the vent plug hole below top plate that was leaking and plan to do it the right way through the reservoir bottle after a pressure test in the spring. I used Quicksilver Gear Lube as usual and let some extra flow out for assurance. didn't fill the reservoir yet. I left the drive tipped up for a week and put cardboard under drive and no oil drips, suggesting the leak is only present when oil level reaches back part of top cap area, when tipped down.

Local parts guy suggested I might have a leak in the large oring that goes under the cap (about 4" in diameter) so got one to install. I have the 12 point socket and a quality torque wrench to use.

I will pressure test in the spring as I don't have access to a gauge now but will then. I know I need to drain the oil prior and possibly pull the drive so pressure is not lost through the dribble valve during test.
The big concern I have now is water being trapped anywhere in the drive. A friend cracked his bell housing when water got trapped beyond the shift shaft seal but his is an Alpha 1 and I know the Bravo 1 is different. Just looking for suggestions to prevent potential freeze problems and hoping I don't need to pull the drive and store separately.

Sorry for being so wordy....just wanted to cover any unknowns

Thanks,
Ted

 

[Bondo]

Ayuh,..... Welcome Aboard,.......
So long as it's been tipped full down to drain the waterline, you should be just fine,.....

 

[Bt Doctur]

 

[etk]

Hi Bondo and BTW Doctour, thank you both for the heads up. I feel confident I got all the water out with the oil as I borrowed one of those metal oil pump cans that pushed out the old lube with a bit of pressure. I have the factory #28 manual and it says nothing about using perfect seal in the large top cap oring but some on forums say to? Any opinions on this? Also, I won't be doing the pressure test till spring but could not find a procedure in the number 28 manual?

 

[Grub54891]

It's not going to hurt putting the perfect seal on there. I'd pressure check now as it will give you all winter to address any issues if they crop up

 

[etk]

Hi All,

Wanted to follow up with what i found. I removed the top cap and the large oring that fits in the groove on the cap looked fine but the other smaller one that's about .625 diameter looked "slightly" out of round (sarcasm intended on the slightly part!) This one seals the shift shift area below it, I believe. After replacing it and carefully installing the top cap without turning it, I tightened to 19 ft lbs, an no oil leaks whether up or down. Prior to that, I poured a small amount(teaspoon) of drive oil where oring goes (where I'm pointing in pic) and it drained down fairly quickly but not sure if it went into the same area as the gear lube or into the shift linkage area (that is not oil filled)? If it connects to the drive lube area housing the gears, clutch, etc right in front of it, then I feel safe, as the lube with water intrusion has all been drained and replaced with new. If it drops into the shift cam, ball detent, shift yoke area (pg 3A-7 in #28 merc manual) I'd be concerned that water could also have leaked into this area and could freeze and crack something? Can anyone verify where this area leads to? I stored the boat away from home in an unheated indoor storage location a few days ago but could revisit to open the rear cover plate if necessary to see if water entered shift assembly? Just not sure if necessary? Thanks again for any suggestions!

Old vs new oring

\"Slightly" out of round....HAR HAR HAR...note sarcasm in slightly!

 

[Grub54891]

I had to fiddlemonky with one of those once. IF I remember correctly, that hole you are pointing to does get oil in it. That's IF I remember correctly.....