Replacing end caps on Bravo III drive


FTL_Alan

FTL_Alan

New member
2008 350 with Bravo III drives. Raised starboard 75% of max, then would not go back down. I have a great mechanic, expert with Mercs. Explained that over time, salt water (regardless how often you rinse the drives) will compromise the ability of the drive's end cap to maintain the pressure required to raise and lower the drive. He got it to go back down by having his helper stand on the drive while hitting the switch. I need new end caps. Anyone had this done? My boat sits on a lift behind my house. Can it be done from my work float, or does boat have to be on the hard?
 
Yes.. when my mechanic was explaining it, we were standing on my dock looking at the boat on the lift, he pointed to the trim cylinders and said the end caps are just behind the zincs, which would be the end of the trim cylinder, where the cylinder meets the zincs.
 
The question is "Do you need new end caps"?

Ahh, maybe, but more then likely you need the packing behind the ends caps. If it was mine I would remove the cylinders, rebuild and re-install (seal kits $29 each).

If I was paying to have it done, I would look into finding some good used ones and rebuild the others later. Suggest OSO wanted section and ask about replacements. Contact "Sick Stinger" he usually has all kinds of this kinds of stuff cheap

Can it be done on the lift?

Sure, easy, no problem so long as it can be gotten to
 
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Do not know what packing All Dodge is talking about? There is no packing inside the end caps. There is a seal kit that comes with the end cap. You need a special spanner wrench or other suitable tool to get them off. Most times they are frozen to the shafts. Yes you can do them on your lift but not recommended. When you remove them keep in mind about 2 quarts of oil will come out of the rams and make a mess if you are on a float. Most guys really don't do them in the water because of this but it can be done. I agree with your mechanic. It is from salt getting inside the seals then they crystallize. When they crystallize they tend to swell up. The trim pump uses over 3000 psi to raise it but only less than 500 psi to lower it and that's your problem. They need to be replaced and I recommend doing both.
 
Removing the cylinders is easy. I would highly recommend replacing the entire assembly rather than rebuilding.
 
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Yes, seals not packing and just a choice of words.

Again must use better words, but my thought was to remove the cylinders and work on a bench, and can be removed on a lift

Removing end caps just takes a pin spanner wrench, but can also make one easy enough and cheep
 
Found this web posting detailing the procedure to rebuild the end caps for a Bravo drive. Not sure if this is for a Bravo III, but would the procedure be the same regardless which Bravo? .. and, is his time estimate correct, i.e. 1-2 hours max for one drive, so 2-4 hours max for two? If yes, I would be able to have an informed conversation with my mechanic regarding an estimate.

Here's the link to the web posting: https://forums.iboats.com/forum/eng...350774-how-to-rebuilding-trim-cilinders-bravo
 
Just to close this posting, here's a photo of the 2008 original end caps, showing the corrosion after 10 years wear. Boat has always been on a lift, not in water, but even on a lift, corrosion eventually takes a toll. The work was done on the boat yard. $930 for parts and labor. Decided to service the drives at the same time, $460 for shaft maintenance and prop polish.

20190302_075251.jpg Capture.JPG
 
Alan,

Thanks for following up!

Why not just replace with a new for both sides; $650 total and the job would have been very easy?
 
I am at the mercy of my mechanic, as I don't have the tools or expertise required to do the work. I learned a lesson recently trying to replace the solenoid on my trim pump. I was told to use a screw driver to jump the solenoid as a test to see if the trim motor would spin. What they failed to tell me before I started, was to make sure to have the battery switches off. Jumping made a huge spark, and I had no ignition at the helm afterward, and the mechanic got to remind me that I don't know what I'm doing and to leave it alone. It was a tough lesson.
 
if the battery switches were off, the test would not have worked... there would have been no power to anything.

Yes, learning is fun and expensive... and sparks sometimes fly!

Me? at 16 I got tired of paying someone $100/hr to fix my Jeep every time some mud got somewhere. Especially when they rip you off... $400 "rebuilt" alternator when they are $150 new? Thanks place I won't name.

Today, at 37, I can rebuild, replace, and tear apart any engine/drive/suspension you can name. Ohh and plumbing, electrical, drywall, insulation... yep. got that.

Today you have the benefit of youtube and wikis and so much online help... I did a transfer case at 20 in a XJ! Long Arm suspension kit on a TJ at 22.

anyway, i'm glad it's fixed now, but don't give up learning :)
 
Yep, I'm using youtube and this forum quite a bit and trying to learn.. see my post on the drive trim issue: http://formulaboatsforum.com/VBFORUM/showthread.php?9139-Drive-Trim-Troubleshooting-Where-to-start

The mechanic did determine that the spark did not cause the loss of ignition. I failed to install the new solenoid in exactly the same position as it was orginally. There is a one-way diode that I wasn't aware had to be put back on in exactly the same way, and of course I reversed it and nothing worked. Simply reversing it got ignition back.
 
Just replace the entire trim ram assembly. Little more expensive, but after 20 yrs, you are on borrowed time anyway. They have had a good life....


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