mercruiser tilt/trim

Question
I have a mercruiser 140hp 1978. the power tilt brings the drive up to maximum very well, but the down will not move at all. I have removed the cylinders on aft end to make sure the drive was not binding (I have just replaced gimbal bearing).
The rams still will not retract with the down button. The pump runs and sounds normal up or down. I have bled the cylinders I had air in them, but the down still doesn't move
Fluid comes out of the down hose when I loosen at the cylinder and run the down button, but I cannot tell how much
pressure it has. I suspect a valve in the pump or a bad reverse lock valve. What do you think? How could I determine
which if either is the problem?























how could I determine which

Answer
Hi Floyd...thank you for selecting the undersigned to reply to your question.

Since you've checked for sources of leakage/air locks and the results were negative, and the rams do not appear to be bent, I suspect you're on the right track for diagnosis and the pump could be the problem.

To be certain, I recommend consulting a qualified and reliable marine mechanic to verify the cause of the problem. You wouldn't want to be caught in a situation where the outdrive might get stuck in the 'up' position while off shore. It's better to be safe than sorry, and the cost will likely be justified.

Safe Boating
Ron