Does anybody have any experience or knowledge about converting the D6D SA from an open center hyraulic system to a closed center system. Can the pump and valves be changed with Cat or after market parts. I want to use the tractor with a laser drag scraper.

Get the right valve for the laser control and it will work with open center systems.

We have a laser system on a tiling plow and when we swapped tractors from a closed center JD to a Steiger with open center, we had to buy another valve manifold to put under the solenoid section and it works just fine. You wouldn't want any other hydraulic circuits to be active at the same time, just the one responding to the laser.

That would take some $$$ you would need to change the vane pump over to a piston pump with a charge pump mounted on it, and you would have to change the bank of control valves mounted on the RH side from open center to closed center. I don't think you will have any luck finding cat hydraulics that will bolt right in without any modifications.



With open ceter hydraulics now they have porportional control valves that vary the flow depending on how far off grade you are and work better than the old "bang bang" valves that are either open or closed. The stiegers when used on the old landlevelers had accumulators to help save the hydraulic system from the constant pulsing caused by the valves quickly opening and closing.

I remember years ago when I was on the ranch there was a hex recessed pipe plug that was on the outlet side of the silinoid control valve that was inside the valve that could be removed to convert it over to open center.

One of the problems with landleveling with lasers as opposed to pulling a tilling machine is the speed that the laser must react inorder to give an accurate grade.