If I put fluid into the base end of cyl 1 and put fluid into the rod side of cyl 2, both cyl will operate , with one pushing and the other pulling.
At the same time, fluid is leaving the other side of cyl 1 and other side of cyl 2.
Why don't you go out to your machine and tell me what fluid is where, and how much.
Will you look at the diagram you posted and tell me why there is a return hose from the steering valve to tank.
Tell me again about no fluid on the other side of the piston.
Just ain't gonna happen.
If I turn the steering about half way, will there be fluid on both sides of the piston.
If I am mistaken, so be it, but I don't think so.
By the way, what is the purpose of the tank return line from the steering valve?
Think about it, even the power steering in your car sends the used fluid to tank.
The steering cyl gets new fluid every time you turn the wheel. Does not matter which way you turn.