Trim tabs don't work.... help!

[Mastercraft]

Trim tabs don't work. Please help!
1) blew fuse
2) replaced fuse
3) trim motors making noise like they run
4) trim tabs don't move

Is it low fluid?
Where is fluid?
Is exact same hydraulic used for something else like engine hatch?

 

[scross]

Trim tabs don't work. Please help!
1) blew fuse
2) replaced fuse
3) trim motors making noise like they run
4) trim tabs don't move

Is it low fluid?
Where is fluid?
Is exact same hydraulic used for something else like engine hatch?

It’s my understanding that the same ATF tank is used for both the hatch and trim tabs. Is your engine hatch working?
If both your trim tabs are not working and failed at the same time then some possible issues like seized hinges, blown piston seal, etc. probably don’t apply.
Definitely check the ATF fluid level as a first step.

 

[Mastercraft]

It’s my understanding that the same ATF tank is used for both the hatch and trim tabs. Is your engine hatch working?
If both your trim tabs are not working and failed at the same time then some possible issues like seized hinges, blown piston seal, etc. probably don’t apply.
Definitely check the ATF fluid level as a first step.

Hatch works.
Not sure when tabs quit working.
Recently had prop speed done to trim tabs when bottom painted. I doubt that any mechanical disassembly would have been required of the tabs to apply prop speed..... correct?

 

[S. Todd]

It is my understanding that on your R29 the same fluid is used for the Bennet Hydraulic Tabs as the engine hatch and if the hatch is open there is not sufficient fluid remaining in the reservoir to then run the tabs. By 2021 when our R29 was built the tabs and engine hatch lift were replaced with electric motors.

 

[dbsea]

Stan, when was the last time you used the tabs? I had all 4 of my hydraulic rams replaced this summer, and then my boat sat in the slip for a few months. When i went to use it last month, I had issues with the tabs and some hydraulic fluid leaking on the water surface. They were making a god-awful groaning noise, and not really working right. I think the cold weather and lack of use are the culprit. I'm going to have to have a haul out to inspect them.... so annoying.

 

[Mastercraft]

I don't know when tabs failed. I would try them every couple months. I cruise at 8-11 knots, so they never seemed very effective but they did work before. Yesterday is when I looked into issue, first found blown fuse, then replaced fuse, trim motor runs, no tab movement. I will check fluid. Where is fluid located?

 

[summer wind]

It's a pretty simple system. Hydraulic fluid could be low, actuators could be damaged, solenoid valves could be stuck. If motor is running, then check the fluid level with the engine hatch closed. It would be surprising that all four of the actuators are damaged, but could happen. Also look for any leaks in the lines or the actuators. If all else fails then you may have stuck valves ( the round cylinders on the pump). The pump should be mounted on the inside of the transum.

 

[OdyseaII]

I had to replace both trim tab cylinders on my R31 CB a couple of years ago. I then sent the damaged ones back to Bennet and they sent me new ones no question.
I think the key is to cycle them regularly.