Abstract: This invention relates to an improved reservoir for power steering fluid which is particularly suitable for use on large vehicles, such as trucks. The improved reservoir of this invention comprises a well to contain a surplus of power steering fluid. The well has an inlet to permit the introduction of fluid from a power steering mechanism into the well, and an outlet to permit the fluid to flow out of the well to the power steering mechanism. The well also has a filter attached over the inlet. The filter comprises a container having a lower chamber, a side chamber, a filter medium and a relief valve. Fluid received in the lower chamber from the inlet pipe flows to the side chamber and through the filter medium from the outside surface to the inside surface, and then out through a center orifice to the well. Fluid at or above a predetermined pressure flows through the pressure relief valve and out through the center orifice to the well.