Still can't get the tilt trim unit to work on my 1993 Johnson 90hp outboard. I have rebuilt all 3 pistons and replaced the screen on the tilt trim motor. Itstill does the exact same thing it was doing before I rebuilt it except now it doesn't leak fluid from the center piston. The motor spins free and seems to spin plenty fast, but it never moves any of the pistons. It is like it is not moving any fluid???? It is full by the way. Yes the manual release screw is closed. Any idea why it wont work??? The coupler is fine as well. I checked it when I had the motor off to replace the filter.