So the large bolt there is a pressure port you would use to feed an external hydraulic attachment with the 3pt hydraulics. I don't recall if it would only work when you pull the 3pt lever, but im pretty sure you will lose 3pt operation if you take pressure from there. I think you're supposed to chain the 3pt in the up position to use that port. I believe the port leads straight into the 3pt lift cylinder so it should only have high pressure when the 3pt is either picking up, or holding up, something heavy.
What is the aluminum block that is already there hooked to? The loader? Generally that's the kind of thing you'd be hooking to to feed an additional hydraulic circuit. BUT, you would not be T'ing off it in 'parallel' as pictured. In 'open center' hydraulics the pressure line actually has no pressure until you move a control valve somewhere, at which point the pressure builds corresponding to the load applied. That's why the line pressurizes when you lift the 3pt 'all the way', because if there's nothing on the 3pt it's only going to take maybe 1-200 psi to lift it, but when it hits the end of its travel it will build pressure up to the relief valve setting, maybe 1500-2000psi guesstimating. Same thing should happen if you held one of the loader valves all the way one way until it stopped moving and just made noise.
So with open center hydraulics you have to hook all your valves up in series, and whichever one is first in line will 'block' all the others when it's in use (unless it has a 'power beyond' port). And the valves themselves have to be compatible with this. With power steering you want it to be FIRST in line so that you don't lose power steering every time you move the loader valve etc.
But even beyond that, for power steering the 'correct' way to do it would be with a flow divider valve. If you don't feed the power steering from a flow divider, the power steering will act differently at different engine rpms, and any turning of the steering wheel will affect the operation of other hydraulics on that circuit. A flow divider aka priority valve (hope im using terms correctly) will make the steering the first thing to get pressure, and limit the flow it gets to a low level that can actually make use of, while sending the rest of the flow to the valves downstream. So if you have an 8gpm pump for example, it only makes 8gpm at redline but makes more like 2 at idle. So the valve for the power steering would send ~1gpm to the power steering all the way from idle to redline, and the rest of the hydraulics would get from 1-7gpm depending on how fast the engine was spinning. The power steering would operate in a consistent fashion and have no effect on the other systems.
Is there a factory power steering version of L245 you can refer to?
