the motor has power tilt/trim. one cylinder has two line fittings for push/pull. the far cylinder is a push only. the cylinder furthest from the pump motor is the push only and seems to hydrolock at about 1/3 of its extension. the guy i got it from told me he had rebuilt them and had disconnected the upper mount from the motor because it was stopping from trimming all the way down. i took the cylinder out and completely apart looking for a problem. even after the hydraulic line was removed it took all my bodyweight to squeeze out the remaining fluid. the thing is that the fitting orifice is not restricted. i confirmed this by disassembling the whole thing inside and out. in the process i wrecked some seals which i replaced(temporarily) with green AC fitting o rings which do seem to seal. i saved the original lower seal which is a square sided o ring. i honed the inside of the cylinder cuz there were two slight scores. i lubed the piston with silicone and it moved nicely after this. what i dont understand is the piston which has an upper and lower seal has about 4-5 inches of travel inside the cylinder. the upper rod of this cylinder is allowed to travel within the length of the piston which is about 6 inches. after learning how to bleed a power trim system via trial and error (and large mess) i did bleed it out. that push only cylinder jammed at the same spot it did before, no longer moving up or down. there is flow thru the bleeder when i open it. im thinking replacement is my only option but i wanna know whats wrong. i also want to know why the cylinder rod is allowed to travel up/down within the piston. after the system was bled, that rod felt like there was compressed air acting as a spring within the piston. the piston itself felt jammed or hydrolocked where it had been stuck before. i dont get it. someone please explain to me the engineering and reason behind this cylinder design and what maybe going wrong. i was going to take it apart again and check the piston, rod, and cylinder for something out of round or bent spot. lastly, im trying not to pour money into this thing but i will do what i have to. thank you
