Hydraulic Trim won't go up. 1996 60hp

[conteco]

The reservoir is full but foamy. It'll go down but not up. The motor is running, but won't go up. Should I replace the entire pump cylinder. I don't think I want to rebuild this? Any ideas?

I know if I call the marine shop they'll tell me to replace the whole unit.

Perplexed,
Conteco

[boats.net]

If it's foamy then it has air in it. Let sit for 20-30 minutes to allow air to escape, loosen the manual realse screw and tilt motor up by hand, top off fluid and let engine trim down on its own, raise back up by hand and top off fluid. Tighten manual realse screw and try again.

[conteco]

Sounds like the same procedure that I use on my floor jack when the pumping gets spongy. I'll try it and try to post if it works.
Thanks,
Conteco