As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FLAP 8 DEGREES GOT HYDRAULIC 1B PUMP CAUTION MESSAGE FOLLOWED BY HYDRAULIC 1B LOW PRESSURE. SYSTEM RAN DRY FOR 20 MINUTES. REPLACED NR 1 ENGINE DRIVEN HYDRAULIC PUMP IAW AMM 29-11-01 AND REPLACED NR 1 ACMP IAW AMM 29-11-03. OPERATIONAL CHECKS GOOD, SN OFF: MX666036. ACMP PN OFF: 848847 SN OFF: MX666036.