I ran the K-planes down, as usual, but when bringing them back up, only the starboard side came up . Needless to say, that was interesting .... The port tab pump runs when I hit the "up" toggle, but it sounds like it is operating in "bypass" mode ... it sounds like it does when you hit the end of the stroke, unfortunately, it is not at the end of the "up" stoke - it doesn't move! I'm going to switch the oil lines at the pump tomorrow to see if I can at least get it to a level position ... that way I can run the boat. Is there a pressure relief valve in the pump that may have gotten stuck, or what? If so, is it something that can be fixed, or do I need to replace the pump? Any suggestions?

One thing that did happen, though, the last time bringing the tab "up", when it worked, the indicator cable bound up, and it mangled the rod end at the tab into a pretzel, so that had been disconnected, but, since it is a mechanical indicator, it should have no effect on the tab operation. Any suggestions?

Thanks,
Bob T.

My port side does the same thing. I have not looked into fixing it but it is and intermitant problem for now. Ii will come back up after playing with the button some, Im sure you've done that though.

Yes ... to the point where I think the thermal overload protection is ready to kick in. The pump runs, just the tab doesn't move (up). Mercruiser parts dot com doesn't show any parts available for the pump, just a new pump! If I knew what was wrong, I would take it to a local hydraulics shop and ask them to fix it.

ITS NOT THE PUMP,,,,,i think its the cylinder.

O-ring bad ,,,so the oil now bypasses in the ram !!!

Easy fix . if you are a little good with your hands ,,u can do it yourself. the o-rings u can by at NAPA !!

I have all the parts to rebuild the cylinder, just need to remember where I put them ... getting old sucks! I'm going to try switching the oil lines at the pump, in the morning to see if that does anything ... that should be easy ... famous last words!

I ran into this problem, exactly as you describe, and it ended up being the coupling between the motor and the pump had failed.

If the motor freewheels after releasing the trim button, this is a likely culprit.

Greg

Bob, crack the hyd. lines loose at the ram and you should be able to pull up the tab. If you can't then the ram has most likely siezed up and will need rebuild. Soulds like what you said that the pump isn't able to move the ram and is bypassing due to the restriction.

This morning I disconnected the lines at the pump. Hit the tab up and down buttons and oil shot out one fitting when I hit the up button, and out the other fitting when I hit the down button. Reversed the lines and reconnected them. Hit the down button and the tab moved right up! Hit the up button and the tab moved down! Exercised it in both directions several times and it worked perfect each time. Reconnected the lines in the correct locations and it works fine. WTF? It didn't sound like the pump was laboring when it was moving the ram. I think I'm going to take the pump apart and clean the valve bodies (if that can be done) when I get a chance.