Abstract: A fluid filter assembly incorporates a filter element and valve assembly within a filter housing and base plate. The filter element and valve assembly is a single pre-assembled unit which includes an anti-drainback valve seat and diaphragm, a by-pass valve assembly, a pleated paper filter element, and a spring endcap. The filter housing and base plate separably clamp together to enclose the filter element/valve cartridge which is replaceable, as a single assembly, once its filtering ability is degraded. The anti-drainback valve seat engages complementary features on the base plate to correctly align and position the filter/valve cartridge during assembly. Further, a recess within the top of the filter housing receives a protrusion on the filter element endcap to provide additional alignment and to provide pressure to seal the filter/valve cartridge to the base plate in a fluid-tight manner.