Power trim trouble shooting

[loulisa]

I have 1994 40hp Mercury 2 stroke and the power trim won't go up. When you activate the Up switch you can hear the motor. I first noticed when getting ready to put in the water this year. Last year, the motor would slowly drop over several days. We would tilt in the up position and come back the following weekend and the motor would be down. This year, the motor won't go up at all.

The powertrim has been taken off the boat and filled with fluid but still doesn't go up. How do I know whether it's the pump/seals or the cylinder (ram)?

[boats.net]

If the motor is working, then most likely it is the valves in the power trim.

[loulisa]

Valve Parts

What parts do I order to replace the valve?

The 40hp 1994, Serial number OG038171

[boats.net]

For this repair, I recommend taking to a knowledgeable technician. There are many intigate parts and require experience.