2008 df115 trim tilt problem

[smarty]

Hi All, I hope someone can help me:

I have the 2008 DF115 outboard. I recently noticed a leak in oil from the tilt unit and lost the power up facility.
I've taken the boat out of the water, opened the manual release and took forever to raise the engine manually but eventually managed to get it up and locked. I lost power up from all switches but had power down. I assume the power problem is the relay assembly but to confirm I was able to change the polarity at the motor by taking off the whole PTT unit - not easy in itself as the engine needs supported etc.
Once the unit is off an in the workshop i have attached it directly to a battery to confirm the pump is ok.
when checking it on the bench the leak became apparent as the O ring on the manual release valve. Sorted that and no longer leaking.
However: even on the bench the unit will only raise a short way and wont hold, it keeps slipping down even with no load on it.
Is there anything else I can check on or repair? or am I looking at replacing the pump assembly unit?

Thanks for any ideas

[artdf175]

The full engine service manual should tell you how to fix that.
However, disconnect the engine trim switch, and test that with an ohm meter to verify that it is working properly
Art

[smarty]

Thanks Art,

I've used the service manual at length to get to the stage I'm at right now. The problem is, even with the unit on a bench and no switches involved (just direct power from a battery) the unit will not hold the tilt rod up. The manual describes the principle of the unit but doesn't appear to offer any clue or troubleshooting for the hydraulic system.