What was found
AT LEVEL OFF, THROTTLES REDUCED TO CRUISE PWR NR 1 ENG OIL PRESS LIGHT CAME ON. OIL PRESS IND 10 PSI. CREW SHUTDOWN ENG. LANDED W/O INCIDENT. MX VERIFIED NO SIGNIFICANT OIL LOSS. C/W ABNORMAL OIL PRESS INSPECT. INSPECT MAIN FILTER AND SCAV PUMP INLET SCREENS & NO DEBRIS NOTED. FOUND OIL FILTER RELIEF VLV (BYPASS) LEAKS. INSPECT & FOUND VLV SEAT INSTALLATION INCORRECT. CORRECTED. R&R ENG DRIVEN OIL PUMP AND PRESS RELEIF VLV ASSY. R&R OIL PRESS X-MTTER. ENGS RUN & NR 1 OIL PRESS FLUCTUATES BETWEEN 5 & 20 PSI. INSPECT OIL SUPPLY SYS & REMOVED DEBRIS FROM OIL TANK AT PUMP SUPPLY OUTLET. MX FLUSHED TANKS & TUBES, RAN ENGS & ADJUSTED RELIEF VLV. SYS OPS CHK NORM IAW MANUALS AND A/C RTS.