What was found
ON CLIMB OUT, DUCT PRESSURES READ 10,000 L 22 PSI ; R 42, FL 190, L 23 - R 43, FL 290, L 23, R 44. WHEN THROTTLES REDUCED AT LEVEL OFF FL 310 THE DUCTS STABILIZED AT 47 PSI EACH. ACFT GROUNDED. ACCOMPLISHED HEALTH CHECK ON NR 1 ENGINE REF T/C NG-36WC-00001. FOUND NR 1 ENG PRE-COOLER CONTROL VALVE AND NR 1 ENG HIGH STAGE VALVE, BAD. REPLACED NR 1, ENG PRE-COOLER CONTROL VALVE. OPS/LEAK CHECKS GOOD REF AMM 36-12-02. REPLACED NR 1, ENG HIGH STAGE VALVE. OPS/LEAK CHECKS NORMAL REF AMM 36-11-06. ETOPS SIGNIFICANT SYS GROUND VERIFICATION ACCOMPLISHED.