A technique facilitates filtration of solids from a well fluid to during a pumping operation. The system may comprise a downhole pump, e.g. a downhole rod lift pump, having a pump housing through which a well fluid is moved during pumping of the well fluid. The pump housing is configured to receive a filter assembly which filters solids from the well fluid during pumping. The filter assembly may comprise a strainer having a filter section and a strainer bushing affixed to the filter section. The filter section may have a plurality of filter holes sized to aid in the filtration of solids. The filter assembly also may comprise a mechanical hold down having an interior sized to receive the filter section. An external bushing is secured to the mechanical hold down in a manner which holds the filter section within the mechanical hold down.