OK, I think I understand what you are referring to….So then you did remove the short little drive pin/spacer between the tilt motor and pump, correct? Does it sound like there is any drag on the tilt motor when you activate it? If not, perhaps you got that drive pin in the wrong spot on the pump. I guess I would just prop the motor all the way up with a board/assistant, then remove the big screw on the opposite side from the tilt motor. You could just put some dexronII in an oil squirt can, then squirt it into the reservoir until it starts spilling out…It won’t take that much, no need to use a gearcase filler pump. I’m assuming that the manual release valve is snugged all the way in.
Once the reservoir is full, and manual release valve is tight, try again, you will have to cycle the unit all the way up/down a few times to get all the air out, then check fluid level again.
Once you have confirmed all this, I guess you will have to pull that tilt motor off again if the motor just seems to free wheel when activated and the pistons don’t move at all….