Bravo 3 Gear Lube Reservoir Leaking?

rmrstlmormrstlmo Member Posts: 222 ✭✭✭

It appears that my gear lube reservoir is leaking.  I have gear lube on the side of engine and in the bilge. I put a real metal clamp on the hose and I'm still getting quite a bit of oil leaking out.  The reservoir will drain after about an hour of running.  Anyone else had this problem?  Any thoughts on what else it could be?  Thanks for you help.

It item 27 in the link below:

https://www.mercruiserparts.com/Show_Pictures3.asp?dnbr=809808 96&ivar=images/COMMON/18730.png&inbr=1943&bnbr=330&bdesc=OIL+RESERVOIR+COMPONENTS

Ray

2006 390

Previous 2000 340

Comments

  • Black_DiamondBlack_Diamond Member Posts: 5,439 ✭✭✭✭✭
    Is it leaking from the reservoir or overflowing from the top? The latter is likely from the drive overheating. Watch over clamping the tube as it's just plastic you are squeezing.

    Past owner of a 2003 342FV
    PC BYC, Holland, MI
  • BoatAwayBoatAway Member Posts: 179 ✭✭✭

    your "on the side of the engine" comment is thought provoking... is it leaking from the hose? have you seen it leak/drip or do you just notice the level go down? It could be that the resevoir is cracked. which happens often..

  • rinker312rinker312 Member Posts: 255 ✭✭

    one time when I took my reservoirs off to clean I remember having the barb assembly on the bottom come loose, but couldn't get it tight without reaching into the bottle with needle nose or something and holding the float assembly in place, then I was able to get the bottom tight. 

    basically the lube bottle connects to the hose and then runs to another connector at the transom.  I don't think there are any connectors in between.  I would try to wipe down all the oil and locate the leak.  Good Luck.

    2004 Rinker 312, 5.0 Merc's, Bravo III, Lake Wheeler, AL

  • BabyboomerBabyboomer Member Posts: 918 mod
    image

    Slip 866 Sunset Marina Byrdstown Tn
  • bat32bat32 Member Posts: 161 ✭✭✭
    I had this problem before I put the drive showers on my Bravo III.  They tend to overheat when up on plane for a while.  It would literally boil out of the vent in the top of the cap. I barely ever run at WOT and still had the problem.  I usually cruise at about 3200-3500 RPM. 

     

  • rmrstlmormrstlmo Member Posts: 222 ✭✭✭

    I've wiped it clean a couple of times and when I check it there is quite a bit of oil on the back side of the resevoir, down the side of the engine, and running down to the bilge.

    I'll do some more investigating this weekend.  I never thought about it coming out the top.  Is there any other way of knowing that the drive is over heating?

    Ray

    2006 390

    Previous 2000 340

  • bat32bat32 Member Posts: 161 ✭✭✭
    If you can pull the boat and look at the drives you will see a white chalking at the top of the drive.

     

  • rmrstlmormrstlmo Member Posts: 222 ✭✭✭
    I believe there might have been some white-ish tint of the lube.  That must be a bad sign?

    Ray

    2006 390

    Previous 2000 340

  • trich11trich11 Member Posts: 108 ✭✭✭
    Any "milky" tint to gear lube usually indicates water in the drives. That is something you need to address quickly.
  • SpeedracerSpeedracer Member Posts: 35 ✭✭
    Are you sure that the thru transom fitting is not cracked?  I believe it is #6 on the above diagram.  I had this problem with my 272 Captiva a couple of years ago
  • 212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    Looking at the various diagrams and schematics, it appears to me that these drives are not dissimilar to differentials on a vehicle, in that the lube is 'splashed' and shouldn't be under any real pressure. 

    Where does it vent? Is the vent obstructed?

    I agree with the above comments, fwiw, in that the lube shouldn't have ANY whitish appearance unless water has been introduced.. that isn't good.. it would be a straight up milkshake if there was a lot, though.. was there a chance the drive was overfilled? Is there a chance it was the wrong viscosity of lube creating over expansion (boiling)? And- how does the drive unit valve between the unit and the reservoir? If whatever valve mechanism isn't valving, it could perpetually overfill the drive, which means it has to vent somewhere..
  • 212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    I just read elsewhere that the only check valve is in the reservoir cap.... huh... it may be you might want to look that diaphragm over and see if it's damaged or stuck... it certainly sounds to me like you have pressure in that system that is causing leaking when it finds somewhere else to relieve itself.. 
  • macgyvermacgyver Member Posts: 3
    I have Alpha's not Bravo's but the reservoir and cap are no doubt similar. My port reservoir was leaking, I switched the port and starboard caps, expecting possibly the leak to switch, but the leak stopped. Inspected caps, and found the port cap had been over tightened at some point, caused gasket to deform. Slight differences in reservoirs made port cap fit better on starboard reservoir.  Fixed gasket. Just another item to inspect.
  • Black_DiamondBlack_Diamond Member Posts: 5,439 ✭✭✭✭✭
    @Drew, at least on the bravo III, and highly likely the other Bravo / Alpha drives are the same, you cannot over fill them, expansion of gear lube fluid is minimal when there is little air in the system and that will bubble out eventually through the reservoir bottle.  Overheating to the point you exceed the limits of the oil is another matter..and of course getting water in the oil means you have other bad problems.

    Past owner of a 2003 342FV
    PC BYC, Holland, MI
  • 212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    aye... gotcha.. it's pressure building that is of concern, and reason I mentioned it..
  • rmrstlmormrstlmo Member Posts: 222 ✭✭✭
    I'll be on the boat tomorrow.  I plan on cleaning it up, refilling and i'lll try switching the caps to see if the leak goes to the other side.  I'll also see how warn the drive feels after running a little while.  Thanks for all the suggestions.

    Ray

    2006 390

    Previous 2000 340

  • bat32bat32 Member Posts: 161 ✭✭✭
    edited June 2013
    Yeah if the oil is white that is totally different.  The chaulking I talking about is actually on the top of the outdrive.  Ther was an extensive post on this on the last site.  But don't feel bad if it is boil over.  The Bravo III's are prone to this.  A hundred dollar pair of drive showers helped mine.  It was so popular on the last site they would do group purchases of them to get a better price.

     

  • rmrstlmormrstlmo Member Posts: 222 ✭✭✭
    The O ring in the cap was missing. Nice to have cheap fix once in a while. Thanks for everyone's help. This forum is fantastic!

    Ray

    2006 390

    Previous 2000 340

  • bat32bat32 Member Posts: 161 ✭✭✭
    Whew.... Good to hear!

     

  • BabyboomerBabyboomer Member Posts: 918 mod
    Good 

    Slip 866 Sunset Marina Byrdstown Tn
  • Dream_InnDream_Inn Member, Moderator Posts: 7,552 mod
    rmrstlmo said:
    The O ring in the cap was missing. Nice to have cheap fix once in a while. Thanks for everyone's help. This forum is fantastic!
    I had the same thing happen to me at the beginning of this year.  Glad you found the problem and it was an easy fix!

    Dream 'Inn III -- 2008 400 Express

  • raybo3raybo3 Administrator Posts: 5,455 admin
    Aways nice to have a nice cheap and easy fix........ =D>
    2002 342 Fiesta Vee PC Point Of Pines YC Revere MA. popyc.org     raybo3@live.com
  • craigswardmtbcraigswardmtb Member Posts: 1,015 ✭✭✭
    I think I have the same issue. Time to switch caps and see what happens.
  • rmrstlmormrstlmo Member Posts: 222 ✭✭✭
    I was able to tell immediately by inspecting both caps side by side. Good luck.

    Ray

    2006 390

    Previous 2000 340

  • dale332dale332 Member Posts: 23
    My reservoir bottle has a crack in the top of it would this cause oil to foam/boil I ask because it only does this after on plane for awhile and as soon as you ease off and idle the oil level goes back down to correct spot? 
  • aero3113aero3113 Member Posts: 8,777 ✭✭✭✭✭
    dale332 said:
    My reservoir bottle has a crack in the top of it would this cause oil to foam/boil I ask because it only does this after on plane for awhile and as soon as you ease off and idle the oil level goes back down to correct spot? 
    Sounds like your drive is overheating? Maybe you need a drive shower to cool it?
    2008 330EC
  • stever3232stever3232 Member Posts: 26 ✭✭
    My gear lube raising and overflows the reservoir  while I am on plane and when I throttle back the level goes down, not sure how to fix 
  • stever3232stever3232 Member Posts: 26 ✭✭
    it overflows because the cap is bad but if the cap was good it would blow the cap off
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