Abstract: A centrifugal pump is quickly and easily fitted with a cartridge-type replacement seal where its impeller shaft emerges from its casing, even though the casing is badly corroded in the region at which the seal is to fit against it. To this end, the impeller shaft is removed from the casing and stripped of its bearings, it being replaced by an arbor that carries a grinding wheel. This arbor is installed in the bearings with the grinding wheel presented toward the corroded surface of the casing. The arbor is rotated and at the same time an axially directed force is applied to it to force the grinding wheel against the corroded casing surface. The grinding wheel removes the corrosion, leaving the casing with a flat ground surface surrounding the bore through which the shaft normally extends out of the housing. The same procedure is repeated at the other end of the housing, if necessary.