Trim/Tilt Hydraulic Pump Issue

[tripod]

2001 E225FHLSIF Trim Tilt hydraulic motor runs fine, but pump would only raise and lower in fits and starts until not at all. Slightly opening manual release valve results in ability to raise motor in fits and starts.

I looked at the parts that I could get to; Manual Release Valve o-rings, Filter, Electric Motor, and Pump Drive, and all look OK. Where should I go from here?

[boats.net]

The valves and seats in valve body are not available without buying new valve body. Might try take apart and cleaning.

[tripod]

OK, Thanks. As it turned out, the pump was air locked. I learned that by trying to re-fill the reservoir after removing the manual release to check the integrity of the O-rings. Fluid came out of the fill port when I re-opened it despite that fluid had drained during the manual release inspection. I had to push fluid in under pressure while operating the tilt/trim switch. That broke the air lock. The tilt/trim works fine now.