Abstract: A flow monitoring device is coupled to a case drain of a hydraulic pump. The flow monitoring device includes a manifold to receive a fluid flow from the case drain. The manifold has an inlet, a throat and an outlet. The manifold includes a pressure sensor to measure a differential pressure of fluid between the inlet and the throat. The manifold further includes a temperature sensor to measure a temperature of fluid flowing through the manifold. A bypass passage is fluidly coupled between the inlet and the outlet of the manifold. A bypass valve located in the bypass passage regulates an amount of fluid flowing from the inlet to the outlet of the manifold through the bypass passage.