What was found
RT ENGINE OIL PRESSURE LOW AFTER TAKEOFF. AC RETURNED FOR MAINTENANCE. AFTER ARRIVAL BACK TO THE AIRPORT, THE PILOT FOUND OIL LEAKING FROM COWLING DRAIN, AND OIL LEVEL WAS LOW. MECHANIC FOUND OIL FILLER CAP SEAL TORN IN HALF. REPLACED SEAL, SERVICED ENGINE, ENGINE WAS WASHED DOWN, RUN UP, AND LEAK CHECKED SATISFACTORY. UPON ARRIVAL, ENGINE WAS REINSPECTED FOR LEAKS AND OIL WAS CHECKED WITHOUT ANY DISCREPANCIES NOTED. ALL WORK PERFORMED IAW MM. (K)