What was found
ON THE RAMP, THE PILOT REPORTED FUEL LEAKING FROM THE INBOARD NR 1 ENGINE DRAIN LINE. MAINTENANCE DISCOVERED THE LOW PRESSURE FUEL PUMP WAS REPLACED. DISASSEMBLY OF THE PUMP REVEALED THAT THE DIAPHRAGM IN THE PRESSURE ADJUSTING VALVE HAD A HOLE IN IT. FURTHER INSPECTION DETERMINED THAT THE PN RA531 DIAPHRAGM CONTROL PLATE, THAT CONTACTS THE DIAPHRAGM, DID NOT CONFORM TO THE LEAR SIEGLER/ ROMEC PLATE DESIGN DRAWING FOR FINAL FINISH OF THE OUTER CIRCUMFERENCE OF THE PLATE. SHARP EDGES THAT REMAIN ON THIS PLATE HAVE THE CAPACITY TO CAUSE A HIGH RATE OF WEAR ON THE RUBBER DIAPHRAGM, CAUSING EARLY FAILURE OF THE DIAPHRAGM AND RESULTING IN FUEL LEAKAGE.