I've watched alot of the norwegians' videos of their dozers, end loaders, excavators, adts, ect; operation looks pretty smooth to me. The way they explained it to me is that pump motor is set to 10% continuous within the radio programming and whichever ch/valve it's mixed with, the more the servo throw - the faster the rpm of the pump motor, the two chs are variably mixed. You want full speed from the pump, move the stick for that valve function to it's full limit. Speed controlled pump saves batt power and decreases heating of the oil, the oil flows fast only when you command it to do so via the tx.
Use a 3 pos switch on tx, in combination with a battleswitch - off/10% throttle/full throttle
Without some volume of airflow thru the inners of the model, what good is an oil cooler
... add a fan = current drain.