I just re-rigged my boat. I have 280s Trim Tabs. I have the pump with the round metal reservoir different from my drive trim pumps that have the plastic reservoir with yellow cap.

I have 2 problems. First I had removed my trim tabs from the boat during the project. That included the pumps and lines and Ram etc. I took the boat out for it's first voyage this weekend. I had tested the trim tabs in the driveway they worked both up and down. I was told these are self bleeding.??? I must still have air in the line or need more fluid. I can move the tab up and down by stepping on it and when I was running it would only go down so far then the water force would push it back up. So ?? how do you bleed these lines so I have full hydraulic pressure.

Second ?? This problem started last year when I put my outdrives up into trailer position my starboard drive would slowly creep all the way back down.(Maybe all the way down over 24 Hrs.). I thought it might have been a leaking drive cyclinder but this year I put in a Brand new Transom assembly, lines Rams etc. I used the old pump. Could the pump itself be leaking back causing it to loose pressure.
Any Ideas on what to fix. ???

Any help is appreciated.

I always run the tabs all the way down until they bottom out and you hear the pump start to strain a little and back up. I do that a few times, checking the reseviour and adding fluid when needed. That's all I usually have to do.

Second problem, since you replaced the transom assembly and rams already, I'd be looking at the pump. They have an internal pressure valve which can sometimes go bad. The valve is used so you don't lock the pump up and fry it when going full up and full down and helps with an impact.

Panther,

I looked at a pump drawing showing the up valve and down valve. If my drive is leaking down do you know if it is the up or down valve that would be leaking or bad.
I will try and add more oil to the Trim Pumps and go up and down a few more times to see if I can get the air out.

Thanks for the response.


Thanks for your

Are you sure on the tabs you have the down side of the cylinder on the high pressure port of the pump?