have a 40 horsepower yamaha 1985 and the trim tilt system was initially jamming with little movement. the motor was running but against a dead head in either direction. finally got the motr to tilt upward and now it won't come down after taking motor off and even opening all possible screws/nuts on the piston with hard pressure some fluid drips out but not without pressure.Seems like there is some plugging or something should i use air pressure to clear passages? the internal parts seem relatively clean any suggestions please before i take the piston completely off?