What was found
DURING APPROACH, PBI BRAKES APPLIED BY LT SEAT PILOT, & ON TOUCHDOWN BRAKES DID NOT SEEMS TO CATCH. FEEL THAT WAY AT TIMES AS THRUST REVERSERS ARE DEPLOYING ON THIS TYPE ACFT, AT ABOUT 70 KNOTS LT SEAT ASKED RT SEAT TO APPLY BRAKES, DIDN'T SEEM TO CATCH. PUSHED PEDALS DOWN QUITE A BIT BEFORE SLOWING. REMOVED DEFECTIVE NR 1, 3 & 4 BRAKE ASSEMBLIES & INSTALLED REPAIRED BRAKE ASSEMBLIES IAW MM. PERFORMED NORMAL BRAKE SYS BLEEDING, PARKING BRAKE SYS BLEEDING, EMERGENCY BRAKE SYS BLEEDING, & NORMAL BRAKE SYS FUNCTIONAL TEST IAW AMM32-40-20. NO DEFECTS NOTED AT THIS TIME.