Fuel pump assembly 10 includes a filter 42 that rests on ledge 48, between the pump housing 22 and inlet cap 56. Filter detector 50 has a valve engager 62 for opening the check valve 58 and bearing feet 52 that engage the perimeter of the filter. When the filter is absent from the pump, the bearing feet 52 of the filter detector move beyond the ledge 48 into the recess 54 and the valve engager stem 62 retracts from the check valve 58 and the valve closes to terminate flow of fuel to the pump. The inlet and outlet caps 56 and 76 are rotatably mounted to the intermediate body of the pump to allow the fuel inlet and outlet to be oriented at angular intervals about the pump. A progressive seal is formed at the O-ring 86 between the inlet end cap 56 and the fuel pump housing to continue the seal as the end cap is removed or reassembled with the housing so that the check valve is closed before the housing is opened.