A fuel filter assembly for a combustion engine, including a two-part filter housing, a filter element, and a restriction sensor, including an external visual display apparatus for indicating when to replace the filter element. As fluid pressure increases within the filter housing, the visual display apparatus correspondingly displays the increase in pressure. When the pressure sensor detects an amount of pressure at or in excess of a predetermined amount, the visual display apparatus indicates replacement of the filter element. A modified embodiment including an electronic pressure sensor and a remote display unit is also described.