Keep pump on or only when moving the cylinders?

[Surge]

Hi, new to hydraulic RC modelling (but not new to RC modelling!).

I have a ScaleArt track dumper, and I noticed that the dump bed will slowly drop when it’s raised, if I raise it and then leave it at that raised position with even a light load (e.g., full of soil).
Is this because the pump is programmed to only run when moving the cylinders? So with the pump off, the bed can move down if there is weight on it?

What’s the general consensus, if any, on whether to keep the pump running all the time, or not?

[RM model Mack]

It should hold its position.

The servo in charge of this function might not be centered and thus it is letting oil through. Try adjusting the subtrim of it as the body is up. I'll bet if you go to like +30 or -30 it will stop.

Would also like to see some pics of this track dumper!