What was found
DURING CLIMB OUT, RT DUCT PRESSURE SHOWED 42 PSI- LT DUCT SHOWED 20 PDI. DURING CRUISE, NOTED DUCT PRESSURES WE NORMAL AT 35 PSI EA. ACFT GROUNDED. PILOTS REPORT LT DUCT PRESSURE 22 PSI RT DUCT PRSSURE 39 PSI AT 38,000 FT .79 MACH, LT DUCT PRESSURE 24 PSI RIGHT DUCT PRESSURE 35 PSI AT 38,000 FEET .77 MACH. WHILE ACCOMPLISHING TC NG-36WC-00001, FOUND PRE-COOLER CONTROL VALVE FAILED STEP 03.F.(5), "PCV DID NOT OPEN WHEN PC IS 3 PSIG OR GREATER" AND HIGH STAGE VALVE FAILED STEP J AT 11 PSIG AND PASSED STEP K. R & R NR 1 PRE-COOLER CONTROL VALVE REF AMM 36-12-02. R & R NR 1 HIGH STAGE VALVE REF AMM 36-11-06. PERFORMED ENGINE 1 BLEED AIR CROSSOVER OPS TEST, TEST PASSED.