Upper bravo 1 seals
 

What is the life expectancy of the upper seals in a bravo?

Also what would cause them to fail?

Thanks,

Mike

You only usually only replace them when they are leaking, damaged or when are rebuilding a unit. They can go bad from dry rotting, harsh chemicals or as a result of impact or mechanical failure.. ;) Jamie / Lakeside

Where is the drive leaking from? That may help us determine the failure.

Dick

Thanks

Had the drive rebuilt about 20~25hrs ago, along with a new gimbal installed. Last time out noticed drive res low after a day on the water, gear lube in the bilge. Still looking for paperwork as to what exactly what was replaced, but if i remember correctly it was upper gear set.

Shop called said seals in the upper were leaking into bellows which leaked into bilge.

Should they wear that fast? Or should I call :bsflag:

No impact, or abuse, usually run 3000~4000 with a few 5000 bursts.

could be leaking at the input shaft seal if it was put together with a grove in the shaft.

There are two seals in the input snout.. One is the seal on the yoke, which holds oil and psi back on the spinnng shaft. The other is the O ring that seals the pinion assembly on the ID of the snout. If that Oring has a tear or the seating surface is marred it could leak. But that would be seen in a leak/psi test more than likely. If it has XR gears in the upper, they produce a lot of psi and the first XR's out had a retainer without a lip and the psi would push the seal forward till it hit the yoke and it would get eaten and big leak. If the upgrade retainer is not used, it will leak.
Just some ideas. But the seals should last 300hrs or so normally without problems.
Hope that helps..
Dick

Is the pressure problem on std B1s too Mr G? My retainers don't have a lip and I just press them in flush with the retainer. You make me think maybe I should have lock tited them or something.

The B1 with helical cut upper gears does not produce as much pressure as the XR's. Be it due to extra heat or what I dont know, just know of the fix for the XR new upper cases when they came out in 2001 or so?

I use red loktite on the seal edge, but there is a sealer on it already. I lightly was the seal with carb cleaner and then the seal retainer. I would not lose any sleep over not using loktite.. If you start to lose oil.. then go look. But typically it is only the XR upper gear set that causes a problem.. I dont recall any XZ's having a problem, although on a rebuild I use the new replacement retainer.

Hope that lets you sleep better.. :)
Dick

It does thanks! Going forward I will use red Locktite in that area just to be safe.

Thanks for the info!