What was found
PRIOR TO DEPARTURE FROM DEN, THE PILOT REPORTED THAT THE LT PNEUMATIC PUMP WAS INOPERATIVE. MX REPLACED THE PNEUMATIC PUMP & THE ACFT DEPARTED, CRUISING AT FL200. THE PILOT NOTED A DECREASE IN POWER & DECREASING OIL PRESS. THE PILOT SHUT DOWN & SECURED THE ENG AS A PRECAUTIONARY MEASURE & DIVERTED TO APA. MX FOUND THE ENG HAD LOST A SIGNIFICANT QTY OF OIL. CLEANED & RAN THE ENG & FOUND THE OIL WAS LEAKING FROM THE PNEUMATIC PUMP MOUNTING PAD. REMOVED THE PUMP FOR INSPECTION, REPLACED THE GASKET & REINSTALLED THE PUMP. GND RUNS WERE SATISFACTORY & NO ADDITIONAL LEAKS WERE FOUND.