What was found
AIRCRAFT DEPARTED NORMALLY AND ON CLIMB-OUT, THE NR 2 OIL PRESSURE ANNUNCIATOR ILLUMINATED BRIEFLY, AIRCRAFT THEN RETURNED TO DEPARTURE AIRPORT. MAINTENANCE INVESTIGATION REVEALED THAT THE NR 2 OIL COOLER WAS LEAKING OIL AND OIL WAS LEAKING FROM THE VERNATHERM VALVE ASSEMBLY. THE OIL COOLER WAS REPLACED AND THE VERNATHERM VALVE ASSEMBLY (45E04-1) WAS TRANSFERRED TO THE NEW OIL COOLER WITH NEW O-RINGS (25C85-128/129/130). GROUND RUNS CARRIED OUT AND NO LEAKS EVIDENT. AIRCRAFT RETURNED TO SERVICE. OIL COOLER REMOVED IS OUT FOR REPAIR AT THIS TIME.