What was found
BRAKING AND DECELERATION SIGNIFICANTLY REDUCED ON LANDING ROLLOUT, BRAKES FELT VERY SOFT. FELT LIKE FULL PEDAL TRAVEL WAS APPLIED. PERFORMED BRAKE BLEEDING WITH PARKING BRAKE SYS IAW TASK 32-44-00-870-801. TAXIED ACFT FOR PERFORMANCE CHECK WITH NO IMPROVEMENT RESULTS. FOUND EVIDENCE OF HYD LEAKAGE FROM NR3 BRAKE ASSY LOWER CYLINDERS. REPLACED NR3 BRAKE. NR4 BRAKE HAS EXCESSIVE CARBON BUILDUP AND SOME EVIDENCE OF HYD SEEPAGE FROM LOWER CYLINDERS. REPLACED NR 4 BRAKE. TAXI CHECK GOOD. RETURNED TO SERVICE.