Busted trim tab piston

[quinsky]

When I put my CW28 on the trailer today I noticed the port trim tab was down and the other one was up. On closer inspection I saw that the bottom of the piston had separated and the spring and shaft were hanging out. Richard is trying to get me a new piston from Bennet. How do I change it out? Will I need to bleed the hydraulic system? It doesn't appear to have lost any hydraulic fluid. The steering, engine hatch and starboard trim tab are all working. Tried to post photo but no luck. here is link.
gallery2.php?g2_itemId=64119&g2_imageViewsIndex=1

 

[CaspersCruiser]

Bennett tab actuators are fairly easy to change, but the failure mode of yours complicates things. That spring is pretty powerful and care will be needed to remove the actuator assembly. Normally, a hose clamp on the shaft is used to keep the spring compressed. I’m not sure if that’s possible the way yours failed.

A valuable resource for Bennett tabs is Tom McGow:

tabmanhelp@gmail.com

He’s very responsive and extremely knowledgeable about Bennett tabs. Send him your picture. If your boat is less than five years old, I’ll bet he will arrange to have a new actuator sent to you. Once you get the new one installed, it is self-bleeding. All that is required is running it up and down a few times. You may have to add a little hydraulic fluid to the tab power pack reservoir. Any automatic transmission fluid will do.

 

[Crewdog]

It was pretty straight forward to change my busted trim tab; sounds like it is very similar to the issue you describe.

see this thread; i've got a picture one screen down:
http://www.tugnuts.com/viewtopic.php?f=5&t=6621&hilit=+trim+tab

 

[quinsky]

Thanks guys. I'm waiting to hear from Bennett. This is another one one of those learning experiences for me. Didn't have trim tabs on my sailboat. After viewing the schematic that Bill provided on an earlier post, I was able to learn the appropriate terminology. Actually the cylinder separated at the bottom and the piston sleeve and spring are protruding out. I'm hoping Bennett will offer me a whole new actuator assembly since its under warranty. If so, I'm thinking its a matter of disconnecting the hose/brass nipple, remove the old one, mount the new one, and reconnect. Of course accessing the hose from inboard will be a challenge as usual. Is the hydraulic system under pressure? When I disconnect the hose will I loose a lot of hydraulic fluid?

 

[CaspersCruiser]

When I replaced the port actuator on my R27, as instructed by Bennett, I left the old upper hinge (part #1 in the diagram from Bill’s post) in place and screwed the new actuator assembly into it. Also as instructed by Bennett, I poured a little automatic transmission fluid (ATF) into the new actuator before screwing it into the upper hinge. That reduces the amount of fluid that needs to be added to the tab hydraulic power unit reservoir. No bleeding was necessary beyond running the tab up and down a few times and then adding a little ATF to the hydraulic power unit reservoir. All of this applies to how the tab system works on a 2012 Ranger Tug. Hopefully a Cutwater owner will post a correction if a Cutwater installation differs.

I changed my actuator because of a persistent minor fluid leak. Even though mine were out of warranty, Bennett sent me a set of replacement cylinder o-rings. Unfortunately, that didn’t resolve the leak so I replaced the actuator. It was only $75. Be sure to get the right actuator. They come in “standard” (A1101A) and “short” (A1200S). My R27 uses the short.