Trim tabs not returning up

[jfkal]

On a boat I am planing to buy one trim tab moves down but does not come up unless nudged by hand. Any ideas?
Thanks
Joerg

 

[snowbird30ds]

Probably crud on the ram, I'm sure they are meant to return by means of a spring inside the ram once the pressure is dropped (at least on bennetts rams).

 

[jfkal]

Thanks.

 

[snowbird30ds]

New rams are about £85 each btw.

 

[matt_lake]

On a boat I am planing to buy one trim tab moves down but does not come up unless nudged by hand. Any ideas?
Thanks
Joerg

I'm assuming these are Bennett tabs. I had the same problem when someone pulled one of mine down while the boat was ashore last Winter. As others have said, they are only powered down and should return on a spring, so long as the piston pulls back when operated by the pump. Check the shafts for growth or damage and assuming they are OK, cycle the tab up/down half a dozen times with the pump. They usually sort themselves out.