mercury 3ram trim tilt problem

[buriy]

I have 1996 mercury 175hp tree ram trim, up works fine, down only big piston, two small pistons going down only by manual release valve. I replace pump, clean pistons and check valve assemblies still have same problem.
Any help?

[boats.net]

If you have trim unit out of motor then trim rams probably wont retract, needs weight of motor to push them back down.