Re: Mercruiser Power Tilt/Trim
I'd just try it out. Run it down and up, watch for any hitches or pauses in the raising/lowering, check to make sure when it's up and you pull on it that the lower unit won't come down (the cylinders should hold it up).
Listen to the pump, if it sounds like it's a cold car engine trying to start it might be worn, or it might just not have enough power. It should sound like a loud whirr/whine noise as long as you hold the button, with a slight winding down/slowing when you reach the limit of the cylinders.
The pump and reservoir are usually located near the engine, at the transom. It looks like an electric motor mounted vertically on a small box, with a sheet metal mounting bracket screwed to the floor. Usually painted all black, with a solenoid on the side, and two hydraulic and several wire connections to it.