Swash plate pump? higher demand higher angle of plate, more friction on slipper pads, case drain filter blockage, more flow generates more heat; excessive high system demand can lead to knock / vibration; jerky operation of hydraulic motors can exacerbate drive shaft wear and cause system lock out ( mainly flaps). Could cause priority valves, where fitted, to hammer leading to such items as extending gear extension time, longer unclean door configuration flight mode.