If the electric tilt/trim motor is functioning when using the up/down switch, well that means the problems lie in the hydraulic system somewhere. If there is no obvious oil leak from the trim/tilt hydraulics, I would guess the oil level or lack of oil is probably not the cause. I suspect you will need to have some one knowledgeable to dismantle the pump/hydraulic system. There are a few seals and o-rings inside which may be faulty. Perhaps a relief valve is corroded stuck. Difficult to diagnose through this column. The bleed screw allows oil to flow freely in and out of the hydraulic ram to oil reservoir thus allowing you to lift or lower manually I've never had to drill one out but in your case, there is probably no other way. Look at a parts book first to see what configuration your bleed screw has. If it's a needle type screw into a seat, be very careful as you go or you could ruin the seat. How about a drill almost the same size and try an ezy-out tool?
