A method of deaerating a mixture of fluid and air according to an example of the present disclosure includes the steps of communicating a mixture of a fluid and air into an open area of a reservoir directly against a wall of the reservoir to separate at least some of the fluid from at least some of the air. The reservoir is disposed about an axis of a rotatable shaft, and the reservoir has a curved radially outer wall and a curved radially inner wall joined by curved end walls that face circumferentially relative to the axis. The mixture is communicated against a first one of the curved end walls. The fluid is held within the reservoir after the separating.