What was found
FLT 1721 FROM FLL TO TOL, AT FL140, AT CLIMB POWER THE NR 1 ENG LOW OIL PRESSURE FILTER BYPASS LIGHT ILLUMINATED. FOLLOWED AOM PROCEDURES A2-10 AND THE NR 1 ENG IN-FLIGHT SHUTDOWN AS A PRECAUTIONARY AND AIR TURN BACK TO FLL. A/C WAS INSPECTED AND THE LOW OIL PRESSURE SWITCH CONNECTOR WAS CLEAN AND THE MAIN OIL SCREEN ON THE NR 1 ENGINE WAS REPLACED AND THE SYSTEM OPS CHECKED GOOD PER B727 MM 72-61-8 AND 72-00, NO LEAKS NOTED DURING ENGINE RUN AND THE AIRCRAFT RETURNED TO SERVICE. THE AIRCRAFT THEN BLOCK OUT AND DURING TAXI, THE LOW OIL PRESSURE FILTER BYPASS LIGHT ILLUMINATED AGAIN. AIRCRAFT THEN RETURNED TO BLOCK. REPLACED THE OIL PRESSURE RELIEF VALVE, THE MAIN ENGINE OIL SCREEN AND THE ENGINE OIL PUMP.