Hydraulic leak in trim tabs

[iceman]

Had our first boating trip of 2014 last week. We had some unseasonably good weather for Northern Calif so we took advantage.

When we got home I was looking in the engine compartment and noticed a pinkish fluid had leaked down from where the hydraulic line for the starboard trim tab goes through the transom. I tested the trim tab and it appears that it's still working, moving up and down like the other one. But clearly the leak needs to be fixed.

The hydraulic line passes through the transom into a "piston" that drives the tab. The hole though the transom is heavily caulked. It appears that the place where the line connects to the piston is embedded within the caulking inside of the hole through the transom. So to fix it, I'd have to dig out the caulk, I guess, replace whatever is leaking, and re-caulk it.

Does my assessment seem correct based on how these trim tabs are installed? I'm not heavily experienced with boat repairs, so anytime a hole in the hull is required it gives me pause. I don't want to breech a watertight seal unless I have to. I could take it to the marine mechanic but if I can do the job I'd prefer that.

Thanks in advance!

[mmwjr]

sunds like you have isolated the issue. The material is a sealant and not caulk. If it's below the water line 3M 5200 if above 4200.

Yes you will need to remove the sealant make the repair then reseal.

[shrew]

That sounds about right. Interesting place to leak. It's not where I would have expected it to fail. The tab will continue working as long as there is sufficient fluid in the resevoir. I suspect you have Bennetts which share a common pump and fluid resevoir. I would probably consider whether I need replace the fluid in the system once the job is done as well. Probably not necessary, but I'm a pessimist and assume that water may have ingressed. Having a compressable substance in a hydraulic system reduces its effectiveness at best. Again, probably not an issue. I've never bled that system before, but I'm sure the instructions are online.

[Tabman]

Hello iceman, I am Tom McGow from Bennett Marine.

Cam you see a brass pipe going through the transom or is it black nylon tubing? Also how old is the boat?

Let me know and I will be delighted to help.

Tom McGow
Bennett Marine

[iceman]

Hi Tom, my name is Tom also. I would welcome your help (and I also appreciate the other comments so far).

It's black nylon tubing. The boat is a 2006 Maxum 2600SE with a single 5.0L MPI merc and a Bravo III outdrive. The trim tabs are Bennetts, and I'm pretty sure there is a common pump.

[Tabman]

Tom,

If you see black nylon tubing entering the inside of the transom you have what we call a pre-connected fitting on the actuator. On other systems we use a pipe nipple with a 90 degree fitting on the end to connect to the tubing, but you would see that if you had it.





The boat will need to be out of the water to fix this. If you send me your name and address in a private message I will send you a new fitting, plus a new top to the actuator (ram) since there is probably a lot of sealant on the one you have now. No charge. This should allow you to remake the connection as good as new.

Tom
Bennett Marine

[mmwjr]

Tabman welcome to the maxium site and thanks for helping.

I have seen you posts on BOC as I hand there as well.

[shrew]

Welcome Aboard Tabman!!

Many thanks for joining and taking the time to help out.

[iceman]

Tom/Tabman:

PM sent. I very very much appreciate your offer to help. It's way above and beyond the call of duty, and a great example of stellar customer service. I will for sure keep you and everyone else updated on how the repair goes. Hopefully it is simple, and I avoid sending the boat to the bottom!

[Tabman]

PM Received, parts on the way.

Tom
Bennett Marine

[iceman]

Tom/Tabman,

Just wanted to let you know I received the parts last weekend. Thanks so much! I did not do the work yet... I noticed that the fluid reservoir was very low, so I added ATF as indicated. The tabs seem to work OK, and I'm not seeing a heavy leak. I have a feeling it leaks worse under load vs up on my trailer, so I'll probably do the repair next weekend.

I also noticed that the starboard tab (the leaky one) had "caulk" around the part that is screwed into the transom, whereas the port tab did not. Seems to suggest that work was done on the starboard tab previously, which would be strange for a 2006 boat. I bought the boat in 2010, and at that time it had only 41 hours on it.

I'll post pics this weekend along with updates as I tackle the repair.

Tom

[mmwjr]

iceman the caulk may have been the PO way of trying to fix the leak.

Don't look a gift horse in the mouth, use the parts supplied and make the proper repair