Trim tab sticks in down position

[R-and-R]

Decided to re-bed my trim tabs. In the process I found that my starboard trim tab will not raise once it's lowered.

Since both cylinders had slight leaks, I replaced both. Unfortunately, that didn't resolve the problem with the starboard side.

I can hear the hydraulic pump activate for both up and down. But the tab will not raise once it's been lowered. I have to open the hydraulic line and allow the cylinder to "spring" up.

I think I know where this is going, just looking for confirmation. I suspect the retract side of the pump solenoid is stuck. This is a 2002 Bennet pump.

 

[Espos4]

Swap the hydraulic lines at the pump and see if the problem moves to the port side tab.

 

[NotHerDecision]

Is the solenoid activating for that side? Anyway the Bennett HPU Pumps really are not that expensive.

 

[R-and-R]

Swap the hydraulic lines at the pump and see if the problem moves to the port side tab.

Yep, problem moves when lines are swapped. Definitely an issue within the HPU.

 

[R-and-R]

Is the solenoid activating for that side? Anyway the Bennett HPU Pumps really are not that expensive.

Solenoid is activating and motor runs in both directions. But tab only moves down, will not move up after extended.

You’re right, I’m surprised at the relatively low cost. Still, $300 is $300. Lol.
But it looks like I’m going that way.

 

[NotHerDecision]

Yes sir. Make sure you undo the fittings and inspect they are in good shape. I believe 2 new ones come with the pump but if not they’re cheap insurance as well as a bottle of fluid.

 

[atrick]

Had same problem on one side, go down wouldn't go back up, selenoid was bad, quick easy fix test with ohm meter and when you unscrew watch the washer under it that it comes out and yoy don't loose it.