A monitoring system may include a position sensor, strain gauges, and a computing device for monitoring valves in a wellbore pressure pump having multiple chambers to determine cavitation in the fluid end of the wellbore pressure pump using strain measurements for each chamber. The strain gauges may determine strain in each chamber of the pressure pump. The position sensor may determine the position of a crankshaft mechanically coupled to a plunger in each chamber. The computing device may receive signals generated by the strain gauges and the position sensor related to the strain in each chamber and the position of the crankshaft, respectively, and may process the signals to determine delays in the actuation of the valves for identifying cavitation and distinguishing cavitation conditions from alternative conditions in the fluid end.