Trim Tilt won't go up - 2002 Mercury 125 hp

[natecollins]

I am having trouble with the trim/tilt unit for a 2002 Mercury 125 hp ELPTO saltwater edition motor I bought recently. The cylinder will not trim up with the load of the outboard motor. The trim pump motor runs. When I have the motor and pump attached without the cylinder, it appears to pump in both directions (I see oil coming out of the ports when pushing the trim button up and down). When the whole system is attached including the cylinder (without the load of the outboard motor), the cylinder rises and lowers in both directions. I had a similar spare trim/tilt system that has a bad motor and cylinder shaft. I used some parts off of that to check my initial trim/trim system. So far I have changed out the pump, valve manifold, cylinder o-rings, and cylinder shell individually to see if any would correct the problem. I think the only pieces that I have not changed out are the pistons inside the cylinder and the relief valve located at the base of the valve manifold (but the o-rings look good). I am struggling at this point and need any help that you can give. Also, I noticed that the manual recommends Automatic Transmission Fluid for this system. Is that the same as Trim and Tilt Fluid (which is what I have been using)?<br /><br />Thanks,<br />Nate <br /><br />Thanks,<br />Nate