Re: power tilt and trim problems
the pump has two parts. motor + valve body. To fix one you need to take both parts off the boat.
bleed down is almost always caused by check valve failure in the valve body. I used to say chinese stuff would be okay on an 85HP but I'm starting to have doubts.
It is such a pain to get pump off engine that it is often worth rebuilding your motor. The red flags for motor are rust stains around top bolts or side gasket joints. If you see either, then go ahead and do motor at same time.
at any rate its not a terribly expensive fix but its not super cheap either. It's cost you $100-$300 and a saturday afternoon.