A magnetic fluid seal is provided located in an L-shaped holder for defining the location of the seal relative to the shaft and bore. The magnetic seal is located inside the knee of the L-shaped holder, with a small magnetic fluid filled gap between the end of the magnetic seal and the fixed shaft. Immediately below the pieces and magnet of the magnetic seal is a gasket which provides for an airtight seal between the edge of the L-shaped holder and the outer wall or rotor. The entire assembly is held reliably in place by a shield which is typically press-fitted in place. The shield is designed to incorporate two key design features; (1) the outside diameter of the shield is a press-fit to the inside of the bore defined by the rotor; and (2) at its final axial location the shield presses vertically against the gasket, whereby the gasket is compressed to an approximate degree (for example about 50%) to provide press fitted contact covering the opening between the seal face outside diameter, and the bore of the rotor, thus providing a complete airtight seal at the outer diameter of the seal.