96 mercury 175 hp. The tilt and trim works fine both up and down at the top of the stroke when it is not on the pistons. But on the down stroke when it first touches the pistons it will not shove the pistons in until the last inch or so. When I let off of the switch it will go ahead and lower itself from the weight of the motor. I filled with fluid and charged the battery and it still does the same thing. Any ideas?