what is a pump?
A device that moves something from one place to another
Your hydraulic (note the correct spelling) pump moves oil from the sump (transmission case) to other places via valves and such
thus, you have a suction side of the pump and a pressure side.
the most common cause of 'no hydraulics' is a suction side issue, be it a plugged filter, plugged suction screen, no fluid, air leaks between the sump and pump, etc etc
on kubota equipment hydraulic pump failure is very very rare; thus always eliminate the other possibilities first.