Mercruiser Bravo II outdrive leaking hydraulic fluid into bilge

Griff44

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Hi all. We have a 2007 Bayliner 325, bought new in 2007. Mercury 250 hp 350 2 barrel engines. Noticed hydraulic fluid entering the bilge from where the 2 hydraulic lines pass through the gimbal housing directly under the engine on the transom. I suspect a loose hose fitting or leaking hydraulic line neat the hydraulic manifold. Has anyone ever seen this problem? Expert opinions are welcome, as I do not look forward to this job.
 

alk

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Welcome to the forum! I will be interested to hear how this works out, as my lines are not looking all that great. The ones outside the boat should be easy enough to replace, but the two running from the manifold up to the drive seem near impossible, at least on my boat. Assuming your pump or reservoir aren’t leaking, there are not that many other failure points inside the boat, just two hoses for each drive. Does this diagram help?

 

Griff44

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Thanks, alk. The job looks like a real pain. Plus, there is a mercathode devise that has to be dealt with. Cable replacement will be from the outside going in through the transom. And it is accomplished with this owner in a kayak. The boat will be up on our 20K Deco lift. Lots of laughs. I wonder if anyone has had to replace one of those pesky hydraulic lines from the manifold?
 

alk

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Ahh, the mercathode wires. I attempted that repair, but never completed it. The merc service manual has instructions about bending piano wire at specified lengths and angles, and using that to fish the mercathode leads through, so I guess the pros can do it. But I didn’t even come close to getting the new wires in. Probably going to give up on the oem location and put on a transom mount mercathode kit this spring.

are you sure your leak isn’t from the pump or reservoir? Seems like the internal hydraulic lines, which don’t have to deal with any strain of motion, would last nearly forever. Although I suppose if the manifold is always in bilge water, corrosion would be a concern. in which case good luck getting the old lines off!
 

LouC

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they can be a bear to get at. Might even be necessary to pull the engine to have access as bad as that sounds. I had all my external ones replaced about 16 years ago along with the external manifold and they still look good.
If you can get access and use a brake line wrench you might bel able to tighten them. You can also get leaks from other sources, like the power steering actuator that is up against the transom and even the lube bottle tube for the drive (if so equipped). I replaced my old leaky steering actuator this past September and it was not an easy job, due to access and also removing the 4 cotter pins from hell. But no more leaks, it leaked for a long time and finally started leaking like a sieve this August. So had to get in there and get 'er done. Had to remove the rear seats and exhaust manifolds to get access.
steerng actuator removal.jpgsteering actuator intalled.jpg
 

Griff44

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Hello again. This little job is coming along. Have only fallen in from the kayak once so far. At the moment the hydraulic manifold will not detach from the gimbal housing. Of course, I have a new manifold and hydraulic hoses to replace the old stuff. My question is how to convince the manifold to detach from the gimbal housing without damaging the gimbal housing? 14 years of gasket glue and corrosion are keeping the manifold attached. Everything looks clean, as I flush and rinse the Bravo II drives ! Your suggestions are welcome.
 

LouC

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very CAREFUL use of heat might work....is it that the bolts won't come out or the bolts are out and the manifold won't separate?
 

Griff44

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The little manifold is held by 2 1/4 inch studs and the gasket glue. I will keep forcing break free at the studs.
 

LouC

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Maybe careful use of a heat gun with an IR temp gun to make sure you don't get it too hot. I have done this before and it works but you have to be really careful.
 

Griff44

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Manifold finally removed! After a week of trying different methods. Had to upgrade to a short 2 1/2 pound sledge, putty knifes, and various special wedges! The manifold was not really stuck by the gasket glue, but debris built up within the gimbal housing. It was like solidified kitty litter and hydraulic oil. Now that its cleaned up, I can install the new hoses, manifold, and mercathode assembly.
 
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