As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DISCREPANCY: PER MAINT CONTROL REQUEST TROUBLESHOOTING OF #2 ENGINE BLEED SYSTEM, BLEED PRESSURE FLUCTUATING IN CLIMB AND DESCENT WITH A 20 PSI SPLIT. CORRECTIVE ACTION: ACCOMPLISHED FIM 36-10-FT-831, FOUND LEFT ISOLATION BYPASS CHECK VALVE WITH SPRINGS DAMAGED, REMOVED AND REPLACED L ISOL CK VALVE PER AMM 36-11-05, LEAK CHECK GOOD. ETOPS GROUND VERIFICATION COMPLIED WITH