Boat Power Trim/Tilt Issue: 1989 90HP Evinrude V4. I emptied the all the trim fluid from the lower valve seal and removed the piston pump control to make sure everything has been drained. In other words, I removed the lower drain plug (part 60) and the piston (part 9) that has an o-ring and 2 springs on it. I put everything back together just the was I found it. I refill the trim until the motor is back to the highest it will go and does not rest on the manual rest. I then lower the trim/tilt until it is all the way down and then for some reason it will not go back up, unless I turn the manual release and pick it up myself. I then drain everything back out to find the o-ring on the piston pump control keep breaking. I have done this 3 times now. Why on earth does the o-ring (part 22)keep breaking? here is the diagram of what I am talking about: http://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1989&hp=90&model=E90TLCEM&manufacturer=Evinrude§ion=Power+Trim%2Ftilt+Hydraulic+Assembly