Should FEL and Remote Hydraulics be affected by the Hydrostat?

[npalen]

Kubota B9200 HST tractor
I've noticed, on occasion, that the operation of the remote hydraulics is affected by what the hydrostat is "doing".
Spinning the wheels in mud, for example, will prevent the top link cylinder from operating when the SCV lever is moved.
Is this just my imagination--are not the hydrostat and other hydraulics seperate systems? Why would one affect the other?

Or maybe its the 3PH that is trying to hold the implement up that is affecting the remote. I was dragging some silt out from under a bridge yesterday in muddy conditions with the heavy box blade so perhaps the 3PH was fighting some "suction" on the box blade.

Edit: For what its worth, my box blade has gauge wheels behind that makes it extra heavy. I normally adjust the depth of cut with the top link cylinder.

Any thoughts on the above?

 

[Fallon]

The HST & other tractor hydraulics are separate systems. The pumps are spun by the same engine & share a common sump of hydraulic fluid. But they are separate systems.

The loader & 3pt are on the same circuit, along with any 3rd functions or other auxiliary hydraulic spools. The 3pt is usually the last one in the loop. So the loader will stop the 3pt from lifting until you stop using the loader.