As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: AIRCRAFT DIFFICULT TO TAXI. #3 AND #4 BRAKES SEEM NOT TO RELEASE ALL THEWAY. TAXI OUT BRAKE TEMPERATURES 10/10/155/145. TOWED BACK TO THE GATE WITH PARKING BRAKE RELEASED 500 PSI REMAINED ON RIGHT BRAKE. TEMPERATURES 5/5/200/190. REPLACED ALTERNATE BRAKES DISTRO DUAL VALVE.