What was found
BRAKE PRESSURE LIGHT: ON TAXI OUT FOR DEPARTURE LO BRK PRESS/ ANTISKID ANNUNCIATOR ILLUMINATED. BRAKE PEDDLE BECAME UNEFFECTIVE. WE STOPPED THE AIRCRAFT WITH THE EMERGENCY BRAKE SYSTEM. ADVISED THE GROUND CONTROL . REQUESTED A STOP INPLACE AND ARRANGED A TOW BACK TO ATLANTIC // SIGNOFF// REMOVED EXISTING HYD PUMP HIGH PRESSURE SWITCH AND REPLACED WITH CUSTOMER SHIPPED OVERHAULED HIGH PRESSURE SWITCH IN REFERENCE WITH CE-560XL AMM 32-44-20 REMOVED AND REPLACED RELAY KZ067. REF CE-560 MM 24-50-03 AND PERFORMED A SATISFACTORY OPERATIONAL CHECK OF THE POWER BRAKE SYSTEM BLED THE BRAKES AFTER SWITCH WAS REPLACED REF DISCREPANCY #2 IN THIS WORK ORDER. NO DEFECT NOTED AT THIS TIME.