The bent washer is called a "spring washer", used to apply some tension or friction force. What's the little plunger looking thingie sitting in the unit in the last pic? Aside from the main O-ring sealing the unit is there another for the rotating shaft where it goes through the cap?
Ok...that plunger...if you look at the rotating cap on the underside of the top piece...it has a notch in it that allows the fluid to push the plunger open letting the fluid push through...the rounded piece of that top cap (un-notched part) keeps that piece pressed closed.
So...I'm making the assumption that it acts as the check valve to keep fluid in the line and pressure on the drive rams to keep them solid when reversing...
But...that's only my assumption.
I'm going to take the rest of the top piece apart in a minute, as I think the fluid is leaking from the top as well.
How'd I do on my guess Rich?