Leaking hydraulic cylinders (trim tabs)

Alpina

Well-known member
Joined
Sep 11, 2020
Messages
188
Fluid Motion Model
C-30 CB
Vessel Name
Alpina
Fortunately I had placed an oil absorbing mat in the bulge under the hydraulic pump for the trim tabs as I had to re-silicone the depth gauge and was drying up the oil from that issue. Saw the hydraulic pump reservoir below full and added hydraulic fluid. Some time later I found a good amount of fluid absorbed by the mat and wondered why. A little research later I learned that the trim tabs have to be fully retracted before adding fluid. Lesson learned but fortunately, not too messy because I happened to have the mat in place.

However, I did notice ATF fluid leaking from the bottom (piston) side of 3 of my 4 actuators. Called Bennett and they owe me a response. Was told there is a lifetime warranty on the hydraulic cylinders. Boat is just a little over two years and old. Am surprised by this as they were as well. Has anyone experienced this so early?

Related, has anyone installed the module from Bennett that auto retracts the tabs? If so, how easy/difficult was it?

Franco


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I personally have not experienced this early on. The trim tab cylinders are durable. The biggest culprit of early failure of the cylinders leaking is leaving them extended out when the the boat is sitting in the water. The composite cylinder shafts need to stay clean. If left extended marine growth starts to develop on the shafts. The growth will cause a abrasive surface which destroys the seals and the cylinders leak. When I say retracted I'm saying completely retracted after each use. If this is not done the longevity of the cylinders will be compromised. This may or may not apply to your use but I'm posting a possible cause.
 
I had to replace all 4 on my R31CB. First 2 were Bennet 3 year warranty, They were very good about it, sent new on credit and when bad ones got back they credited me. Next 2 out, but not as expensive hauling to replace.
 
BB marine":2hiobunz said:
I personally have not experienced this early on. The trim tab cylinders are durable. The biggest culprit of early failure of the cylinders leaking is leaving them extended out when the the boat is sitting in the water. The composite cylinder shafts need to stay clean. If left extended marine growth starts to develop on the shafts. The growth will cause a abrasive surface which destroys the seals and the cylinders leak. When I say retracted I'm saying completely retracted after each use. If this is not done the longevity of the cylinders will be compromised. This may or may not apply to your use but I'm posting a possible cause.
Makes sense. Will make this a habit. Wonder why they don’t set them to auto retract from the factory.


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Alpina":3i9mpnsj said:
BB marine":3i9mpnsj said:
Wonder why they don’t set them to auto retract from the factory.

The tabs on my 2021 RT27 do retract when the engine is shut down...
 
GypsyMoth":18us3415 said:
Alpina":18us3415 said:
BB marine":18us3415 said:
Wonder why they don’t set them to auto retract from the factory.

The tabs on my 2021 RT27 do retract when the engine is shut down...

R 27 outboard has Lenco electric trim tabs are not Bennett tabs. Bennett has auto retract tabs but they are an install option.


I retract the tabs as part of my engine shut down. Shut engine down, turn auto pilot off, retract trim tabs.
 
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