DF40 Replaced o-rings but still have prob

[Texigent]

Replaced the o-rings in the auto trim unit but the original problem remains... "up" trim works fine, "down" trim does not lower the motor, but the trim motor is working (buzzes but doesn't run the pump) and, doesn't lower the motor. Can this be a problem with the sender unit?

[catacom225]

You will need to bleed the air out, Simply lift engine up and then lowering by turning the manual release valve once down tighten screw and repeat several times checking oil level each time