What was found
AFTER LANDING WHILE TAXING TO THE RAMP, WE EXPERIENCED SIGNIFICANT CHATTERING WHILE APPLYING THE BRAKES. THE AIRCRAFT WAS DIFFICULT TO TURN AND STOP SMOOTHLY. CHECKED THE SERVICING OF THE HYDRAULICS IAW AMM 12-13-00 NO FAULTS NOTED. CHECKED THE TREAD DEPTH ON RT 4/32 AND LT 3/32, CHECKED RT BRAKE WEAR PIN RT 8/16 AND LT 8/16, PERFORMED BLEEDING OF MAIN HYD SYS 6 TIMES IAW AMM CH. 32-40-00. REMOVED SOME AIR FROM BRAKES. SERVICED THE HYDRAULIC RESERVOIR WHILE BLEEDING IT DOWN TO THE CORRECT SERVICING GOT A GOOD AMOUNT OF AIR OUT OF THE SYSTEM. PERFORMED BLEEDING ONE MORE TIME THEN TAXIED AROUND THE RAMP IAW AMM 09-20-01 NO FAULTS NOTED.