As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: PILOT REPORTS DURING TAXI OUT IT WAS DIFFICULT TO MAINTAIN TAXI SPEED. BRAKE TEMPS INDICATE 70 67 92 210. #4 BRAKE IS HANGING UP. MAINTENANCE REMOVED AND REPLACED #4 BRAKE ASSY IAW AMM 32-49-11. LEAK CHECK GOOD. TEMP NORMAL.