What was found
(CAN) WHEN CREW APPLIED PARK BRAKE ON THE TAXI WAY THEY HEARD A NOISE AND THE RT PEDAL ON BOTH SIDES LOST ALL RESISTANCE WHEN APPLIED. RETURNED TO GATE. RESOLVED ON W/O: 390727, TASKCARD: NR-00001. RT BRAKE CONTROL VALVE CABLE FOUND BROKEN, CABLE REPLACED IAW AMM 20-60-01, 32-42-21. AREA WHERE CABLE BROKE WAS INSPECTED, PULLEY AND SURROUNDING STRUCTURE AND BOROSCOPED WITH NO DAMAGE FOUND. INTERRIOR REINSTALLED AND FUNCTIOND CHECKED IAW 25-21-47. RII CARRIED OUT FOR REPLACED CABLE SECURITY AND REINSTALATION OF ACCESS PANELS AND INTERIOR COMPLETED.