Mystery Bravo Oil Leak
 

Over the last 20 or so hours I've noticed a loss of drive oil on my port motor. Starboard has not moved since I bought the boat a month ago. It's a 2000 Fountain EX w/ 500efi's. I've gone through about a quart on the port drive through the bottle in less than 20 hours. I never see evidence of the leak in the driveway or in the water. No puddles or slicks. Upon general inspection I can't find anywhere the oil would be going. There's nothing in the bilge as far as I can tell. The bottle has no cracks or leaks. I can't see where the line goes through the transom due to access issues. Was just wondering if anyone out there can give me an idea of where to start looking, or if they've dealt with the problem before. I've searched the forums, but no one ever lists a solution. The only difference I can tell from one drive to the other is that the leaking one seems to be dirty (black) inside the hub of the propeller- the starboard is spotless. Any ideas, let me know guys!

Ben

Going out the propshaft seal while under way - could be fishline, or intenral issues and about to go BANG! Get it apart and find out why.

When you pull the drive look in the bellows area. There is a seal on the input shaft, if it leaks it will go into the bellows and is hard to find in the boat.

Pull the drive. Be prepared when the drive comes off all of the oil sitting in the bellows will come pouring out at you.

Wouldn't hurt to check the O-ring on the top cap of the drive either.

I haven't pulled my drives before. I have all the tools and am fairly confident in my mechanical abilities, but this is new to me. I do have a Bravo service manual that I picked up from a guy on here, so that should help. Are there any special tools needed to do this type of work on the drive? Sounds like the prop shaft seals are better left to a merc mechanic, but I think I could figure out the bellows area. Any further input would be appreciated. Thanks!

No special tools needed. Pulling the drive off is not a problem. 6 nuts and it should come off depending on your steering too. make sure your shifter cable releases when you pull the drive off. Once its off you might need a drive guy to do the repairs. I had the same issues as you and it was all in the bellows. The seal on the input shaft went bad. I would have help being your first time....no need in dropping that drive on your foot!

It could very well be the seal in front of the drive as others have indicated as well. Make sure the drive is in neutral before removing it.

could be the yoke seal, shift shaft seal or the o-ring in the top cover for the shift shaft. That's my guess!

And the winner is.... input shaft seal. Took it down to my mechanic had me out the door in 3 hours. No more disappearing drive oil. :)