What was found
BRK FAIL YELLOW CAS: ON TAXI, YELLOW BRAKE FAIL MESSAGE ILLUMINATED. NEITHER PILOTS BRAKES WERE OPERATIONAL WITH THE CAS ILLUMINATED. HAD TO USE EMERGENCY BRAKE TO STOP AIRCRAFT FROM TAXIING. REMOVED "FAULTY" BRAKE CONTROL MODULE DAP00101-02 SN 019RK AND INSTALLED A "REPAIRED" UNIT PN: DAP00101-02. SN 75LP. BLED SYSTEM AND PERFORMED FUNCTIONAL CHECK. AS A PERCAUTION, PERFORMED TAXI CHECK WITH NO FAULTS OR DEFECTS NOTED. ALL WORK ACCOMPLISHED IN REFERENCE TO EMB AMM 32-41-07. LEAK CHECK AND OPS CHECK FOUND TO BE SATISFACTORY AT THIS TIME.