Trim pump runs but sterndrive won't raise or lower

[Riegfrghtl]

I have a 1972 mercruiser 888 with a prestolite trim pump. Trim has worked fine up until this past weekend. Trim pump will run in the up or down postion but sterndrive will not raise or lower. Boat is in the water at my slip in the marina so I haven't pulled it out yet to check trim cylinders or hoses. There is no trim fluid leaking into the bilge or in the water surrounding the boat. Is it possible for u-joint to seize up causing the sterndrive to stay in one position. If not, can anyone point me in the right direction to get started in fixing this problem? Thanks in advance for any and all suggestions!

Tim

 

[Riegfrghtl]

Re: Trim pump runs but sterndrive won't raise or lower

Off to reread the manuals!

 

[JWebber]

Re: Trim pump runs but sterndrive won't raise or lower

Is your fluid level up? Got enough in there?

 

[Riegfrghtl]

Re: Trim pump runs but sterndrive won't raise or lower

Fluid level is right where it is supposed to be according to service manuals. No visible leaks in bilge or in water surrounding sterndrive. Pump runs in up and down position, sterndrive just does not move, not even a little bit!. Beginning to think something is stuck like cylinders, hinge pins, or universal. Everything was greased at beginning of season. Any suggestions of help will be greatly appreciated!

Tim

 

[JWebber]

Re: Trim pump runs but sterndrive won't raise or lower

Disconnect the ram arms from outdrive if you can. Then try to cycle up and down. Also see if you can move the drive with your hands up and down without friction. But these systems pump high psi fluid thru it so I doubt it's the drive obstructing the rams from pumping, but having it disconnected will help troubleshoot. Could be the pump of the valving system under the pump.

 

[Riegfrghtl]

Re: Trim pump runs but sterndrive won't raise or lower

Thanks JWebber will do as you suggested!