'90 70ETLD Power Tilt Issue

[Art42]

Please help!! So the power tilt/trim unit will push the motor up but not hold. Have had minor leak from one trim piston for a year. Motor falls rapidly through tilt cylinder and significantly slows at trim cylinders, with no external leaking. Leads me to believe it could be something bad in the manual release valve. Tried to get the unit out and can not for the life of me figure out how the damn thing comes out. I feel like im pkaying with Yamaha's version of the rubics cube. Anyone remove one of these units before?! Any help much appreciated.

 

[nccatfisher]

I would suggest a factory service manual for that model.