i have a 90 model 60 hp johnson on my pontoon.power trim worked flawlessly two seasons ago did not operated boat in any way for two years.can lift motor to highest position manually and it will hold there but operate trim switch in either direction and it goes down .once there it will not raise itself. if i lift motoer manuallyand operate switch up the two outer cylinders will both extend and if i operate it down they both retract however they wil not do this with the weight of motor on them.in the water if i raise motor manually and put under load it will hold whatever position i lifted it to so i dont believe any of the cylinders are leaking.any ideas on what problem could be? i have changed fluid and blead all air out and seems like maybe for some reason its just not making enough pressure?