What was found
DURING TAXI OUT, IT REQUIRED COMPLETE RUDDER PEDAL COMPRESSION TO ENGAGE THE BRAKES. TROUBLESHOT, REMOVED AND REPLACED POWER BRAKE VALVE. PERFORMED BRAKE SYSTEM FUNCTIONAL TESTING, NO DISCREPANCIES NOTED AT THIS TIME. SERVICES HYDRAULIC RESERVOIR. PERFORMED OPERATIONAL TEST, NO DISCREPANCIES NOTED AT THIS TIME. IAW AMM 32-40-00 & 12-10-00.