As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) BRAKE FAIL CAS FOLLOWED BY HYD FAIL CAS DURING TAXI OUT. HYDRAULIC PRESSURE RETURNED, BUT BRAKE FAIL CAS REMAINED. ACFT TAXIED BACK TO CHOCKS. CMC/CVFDR DOWNLOADS PERFORMED. FORWARDED TO MFG ENGINEERS, SUGGEST REPLACEMENT OF HYDRAULIC POWER PACK.