deutz hydralic clutch cooling fan

My Dx-6.05 has an also Deutz F6L912 with a hydraulically clutched fan. It used engine oil pressure to engage the fan when hot. I'm removing it all and replacing with a full-time direct-driven fan but have cleaned up the pieces and and am trying to figure out how it all works. Anyone familiar with this system? (I have been unable to find a manual for this tractor).

There's a control-tree inserted into the rear of the exhaust manifold. It gets full-time oil from the oil filter fitting (rear line on right with arrow from right, not to confuse with loose line hanging behind it). This oil I assume is continuously passed through "L" to lubricate the fan bearings and conditionally throught "H" to engage the clutch when warm. The black line "E" is a mystery, it's a 1/2" air connection between the fan-blown pressure duct and the this fitting, I have NO IDEA what it does or how it does it.



The above is part one of the question.



The second part shows the same continuous-flow line "L" routing to what looks like a solenoid valve the other side of which is connected to the conditional lilne "H" also from the previous picture AS WELL AS WHAT LOOKS LIKE A BALANCING BRIDGE WITH THE "L" line. This part really has me stumped. (The lines at the fan are not connected because this fan does not have the clutch)

On those engines, the blower should be thermistatically controlled otherwise the engine will run cold if used in winter weather. The little bolt with the integral stem should (I believe) have about a 2mm washer under the head to allow the blower to run thermostatically . If i remember correctly, you remove the washer to allow the blower to run full time

With a blower this 6 hole 912 is also a popular truck engine, I wonder if they use the clutch oin those? The F4L912 I built in 2008 came from a shovel and what it had was a thermostat controlled flap restricting the outflow air from the the boxed-in cylinders. I haven't decided yet but I might go for some serious temperature-watching system and a manually controlled star-louvre in front of the fan.