A reservoir assembly for retaining a fluid includes a body having a base and external side walls defining a cavity. A baffle has a top surface spanning the cavity and includes a peripheral wall substantially conforming to the external side walls and extending to the base. A lid is connected to the body. The cavity is divided into a first, second and third compartment by a cooperation between the top surface of the baffle, a plurality of walls of the baffle, the base of the body and the external side walls of the body. The first and second compartments are in fluid communication with each other through the third compartment. An inlet port and an outlet port for allowing fluid to enter and exit the cavity are fluidly connected to the body and are fluidly connected to each other by the first compartment to direct a flow of the fluid.