Bravo 1 Sterndrive

[lknlover]

I just had my Bravo 1 outdrive rebuilt due to a faulty yokeseal and since re-installed it has drained an entire oil reserve reservoir. Since out first trip out where 1/2 inch or more disappeared - refilled- then overnight lost 1/8" in about 24 hours and another 1/8" after a good ride - WOT 75mph. The drive is connected to a 500HP -

How much oil should have been consumed once the drive has been ridden?

Will it stop after a couple of times out or is something else wrong?

I will check the levels again in the morning. The mechanic wants to pull it again but if he does I won't see it for quite awhile as he is covered up with business.

Help me decide! Did you all follow this? I hope so.

 

[QC]

Re: Bravo 1 Sterndrive

If it was filled right, it should not take much at all to settle. Who knows how they behave with 500 bhp continuous going into them, but I wouldn't expect them to use much or any. If your mechanic is concerned, I would be too.

 

[HT32BSX115]

Re: Bravo 1 Sterndrive

Howdy,

When I drained and refilled my Bravo III with Merc synthetic oil, it foamed up quite a bit on the first run.....indicating that there was more than just a few bubbles in there after filling.......

After the first run the drive sucked most of the oil right out of the container on the engine back into the drive as it cooled down. Subsequent runs it did it less and less until after about 3 or 4 runs there was no more foam and the level didn't change much at all.

Each time I ran it there were some bubbles in the reservoir.(but less each time)

As the bubbles came to the top I had to add a little oil to keep the reservoir filled.


I didn't do any 75 mph runs ...........I could only get it to do a little shy of 60......but I'm only about 330hp (stock 454) at the crank.

Drives do not "consume" drive oil any more than a rear axle does. (which is, not at all)

If it appears to be losing oil, it's leaking out or you had a huge bubble in the drive (it was filled from the bottom, right?) (I hope)


Cheers,


Rick

 

[lknlover]

Re: Bravo 1 Sterndrive

The mechanic came back and removed the drive to check his repair and no oil was present in anything he did. Next... - must be the prop seal but if it was the prop seal shouldn't the oil be leaking out of the prop area? It isn't so he put it back on and filled it with oil again and said to "watch it".

We really cleaned out the bilge and wiped down the entire engine to remove any oil that was present to try and locate where the missing oil is going - at this point we have no idea. There has been some water in the bilge but the boat has been on a trailer covered and I think some rain may have gotten in. There is usually no water present as it usually lives under roof.

So the boat goes back in for test ride #3.

The oil in the reservoir rises about 1/4 inch when the engine has just been run then it drops back to the previous start level and continues to fall until 1/2 inch under the fill line?

Officially the loss is a total of 2 1/2 inches of drive oil since the stern drive was put back on. The yoke seal was the original dx and repaired but it's still not right.

Anybody have any ideas?

 

[Don S]

Re: Bravo 1 Sterndrive

If you have no oil in the bellows, the yoke seal is Not your problem.
The best thing you could do remove the drive, drain all the lube out of it, then do a pressure check of the drive. You don't have water getting into the lube, so the vacuum check won't help. You are loosing oil as the drive heats up.

 

[lknlover]

Re: Bravo 1 Sterndrive

If you have no oil in the bellows, the yoke seal is Not your problem.
The best thing you could do remove the drive, drain all the lube out of it, then do a pressure check of the drive. You don't have water getting into the lube, so the vacuum check won't help. You are loosing oil as the drive heats up.

At first there was oil disappearing and it was located in the bellows thus the yoke seal repair was done. If there was another source it was unknown at that time. How odd that 2 things appear at exactly the same time causing the gear lube to drop.

The mechanic said he did a pressure check before the first test ride and all was good. When he was here yesterday he didn't bring the thing to check the pressure again because he was convinced it must have been something he had done during the 1st repair.

He has no idea as far as what else it could be. I guess if we don't stop losing oil he'll come back and do a pressure check again.

One other angle was that the gear lube tube was leaking --which it isn't.

More ideas - please

 

[Don S]

Re: Bravo 1 Sterndrive

How odd that 2 things appear at exactly the same time causing the gear lube to drop.

Did you mechanic do a pressure check on the drive after repairing the yoke seal?
If not, shame on him.

Personally, when I have to replace a seal on any outdrive, all the oil is drained, the drive pressure and vacuum checked. When it passes the tests, new gear lube is put in, and the drive reinstalled.

 

[Anchor Management 1]

Re: Bravo 1 Sterndrive

I just fixed the same issue, when someone put the drive on the o-ring fell out of place between the drive and gimbal housing.

 

[lknlover]

Re: Bravo 1 Sterndrive

Anchor Management 1,

I like your idea of a lost o-ring.

I'm convinced when the drive was off something was left out thus causing the continued leak of oil. What you mention makes total sense - I'll call my mechanic tomorrow and ask him about that o-ring.

The drive was pressure checked either before or when it went back on the boat. Would a missing o-ring show up on the pressure check?

 

[lknlover]

Re: Bravo 1 Sterndrive

One more question - where would the oil go if the o-ring was missing?

 

[Anchor Management 1]

Re: Bravo 1 Sterndrive

That depends on if the drive was on the boat when it was pressurized or not.

 

[lknlover]

Re: Bravo 1 Sterndrive

That depends on if the drive was on the boat when it was pressurized or not.

Tell me more...

Why does it make any difference if it was off or on the boat?

I honestly have no idea if it was pressure tested on or off the boat - when they came to re-install it the 1st time it got dark and the mechanic was wearing a head lamp so the idea of an o-ring falling off could be a possibility but wouldn't he have seen that it was missing the second time the drive was taken off the boat?

I'm a chick and motors are not my strength so please help me understand.

 

[Anchor Management 1]

Re: Bravo 1 Sterndrive

If the drive is on the boat ,the pressure check could hold but the gasket on the res. in the boat could leak air .If the drive is off the boat you totaly remove the boat end of the pressure check.If it was checked on the boat after you seen the leak oil will come out between the drive and where it bolts too.