Bennett trim tabs repair?

Lucrative

Petty Officer 3rd Class
Joined
May 8, 2015
Messages
96
I recently was noticed my trim tabs stopped working and realized I was low on trim fluid, so I refilled it. After refilling, I realized I had fluid in my bilge, which I have found has come from my trim tabs. I checked it out, and it looks like its coming from somewhere in the through-transom hole. There is a fluid line that runs to a 90 elbow, and through the transom, which is where the leak appears to be coming from. Upon further investigation, I have noticed that on both sides trim cylinders are leaking on the outside from the area around the top of the cylinder.

Question is, are these things shot or should I try to repair them? How tough is the repair if it is possible?
 

spoilsofwar

Lieutenant Junior Grade
Joined
Jun 29, 2011
Messages
1,124
Standby for user Tabman... He'll be along shortly with all the help you could ever need.
 

Tabman

iboats.com Partner
Joined
Feb 21, 2002
Messages
566
I recently was noticed my trim tabs stopped working and realized I was low on trim fluid, so I refilled it. After refilling, I realized I had fluid in my bilge, which I have found has come from my trim tabs. I checked it out, and it looks like its coming from somewhere in the through-transom hole. There is a fluid line that runs to a 90 elbow, and through the transom, which is where the leak appears to be coming from. Upon further investigation, I have noticed that on both sides trim cylinders are leaking on the outside from the area around the top of the cylinder.

Question is, are these things shot or should I try to repair them? How tough is the repair if it is possible?

Can you tell me how old the system might be and what type of boat it is on?

Outside is the fluid leaking here the triangular part is on the transom or where the cylinder body screws into the top part?

Any way you can post a photo of the Tabs and actuators (rams)?

They are almost always repairable!

Let me know and we can go from there,

Tom
Bennett Marine
 

Lucrative

Petty Officer 3rd Class
Joined
May 8, 2015
Messages
96
Sorry, it is giving me a really hard time uploading a picture on here. Saying the file is too big. It's 2.7 mb and it can only be 2 mb apparently. It's just pictures I took with my phone, so not sure what to do about that. If you have an email, I can easily send them to you there. I just can't get this to work for me.

As for the information you asked for:

It's a 2000 Chaparral 270. I've owned the boat for only the last 2 years, and I'm assuming the tabs are original to the boat, so we're looking at the possibility that they are 16 years old. The boat was kept in dry storage for the first 14 years of it's life, and run sparingly, so the tabs actually appear to be in good condition.

The leaks on the outside of the boat are not coming from the triangular section, but on the cylinder body from what I'd call the cylinder cap I guess. Not sure what the proper term for it is.

On the inside where it's leaking into the bilge, it appears to be from the connection where the 90 degree elbow goes out through the transom.

Thanks!
 

Lucrative

Petty Officer 3rd Class
Joined
May 8, 2015
Messages
96
Yeah, my phone takes pictures that are 2.7mb. So there is no way for me to post them....
 

Tabman

iboats.com Partner
Joined
Feb 21, 2002
Messages
566
Try grabbing the cylinder body and giving it a firm clockwise twist and see if that stops the leak, if not the O-ring there can be replaced, send me your name and address.

Also take a 1/2" wrench and see if you can tighten the nut where the tubing goes into that 90 degree fitting.

Let me know how it goes,
Tom
Bennett Marine
 

Lucrative

Petty Officer 3rd Class
Joined
May 8, 2015
Messages
96
I'll try turning the cylinders. As for the other part, I'd have to turn the 90 degree fitting to tighten up where it's leaking. It's not the connection from the tubing to the fitting, it's after that, on the other side of the fitting, where it goes through the transom. Is that part threaded as well? Should I disconnect the fluid line and try to turn the 90?
 

Tabman

iboats.com Partner
Joined
Feb 21, 2002
Messages
566
You can try that but only rotate it 1/2 a turn or so, if you turn it too far you can strip the threads or block the fluid path.

Do you have Trim Tab position indicators on the dashboard?

Tom
Bennett Marine
 

Lucrative

Petty Officer 3rd Class
Joined
May 8, 2015
Messages
96
Hey Tabman. I had the boat out yesterday and I tried tightening everything up. It appears that it worked on the leaks by the cylinder caps, because I don't see any sign of the ATF fluid around the cap there, but not for the leak into the bilge. I gave the 90 a half turn and it still leaked (slowed it down a little) then another half turn and it was basically the same at that point. I didn't want to go any further for fear of stripping it like you mentioned.

I do not have trim tab indicators on the dash board. Where do I go from here on the leak going into the engine compartment?

Thanks for your help!

Luc
 

Tabman

iboats.com Partner
Joined
Feb 21, 2002
Messages
566
Luc,

The boat will have to be out of the water and the upper part of the actuator will need to be replaced. To make sure you get the correct part we will need to know if there is about 1" of piston shaft exposed when the Tabs are all the way up, or if the lower hinge almost touches the cylinder body.

I am on vacation and on the road so my reply may be delayed.

Tom
Bennett Marine
 
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