What was found
LOW OIL PRESSURE ON NR 1 ENGINE REQUIRED PRECAUTIONARY SHUT-DOWN. (OIL LIGHT ILLUMINATED AND PRESSURE DROPPED SLOWLY TO 40 PSI AND SHUT-DOWN WAS INITIATED.) MASTER WARNING FLASHED WITHOUT CAPTION. REMOVED AND REPLACED OIL COOLER IAW MM. GROUND RAN AIRCRAFT. OPS CHECK AND LEAK CHECK GOOD, NO DEFECTS NOTED. AIRCRAFT RETURNED TO SERVICE. AIRCRAFT TOTAL CYCLES, 12,113. (X)