[pugs]

The pump is a "fixed displacement" pump
The valve is most likely a closed center, meaning the center neutral posistion is closed to any oilflow. You can also get valves (not sure about in the small RC stuff) that are open center for additional valve blocks or what not beyond the first.

It may be possible to add an additonal work valve and have its cylinder port tied back to tank port, and adjust the transmitter computer to move that servo to full open posistion anytime any other valve is not being used for X amount of time. This would effectively act like a pressure dump valve and remove load from the pump motor. The oil would still heat up as it is being pumped around, just not as fast of heat buildup as if it were under pressure. Could also be done with a solenoid and a few limit switches or prox switches to detect the primary valves center posistion, this method would not use a valuable radio channel.

The ideal setup, being that the pump is electrically driven would be to have the pump shutoff when there is no demand for oil flow, would probably want a check valve at the pump outlet so that if a valve were opened and the pump for some reason was not on a loaded cylinder would not cause the load to suddenly drop by turning the pump in reverse.

I think there is a switch some of the guys have been using that turns the pump on and off as needed, can't recall the name of it.

Depending on the valve construction, one might be able to modify it to be an "power beyond" valve and have the power beyond dump to tank. It has to be built such that any spool movement to feed a cylinder then blocks off the power beyond port. Normally the power beyond port would feed a secondary valve block which you don't want to be operable when the primary is being used.