As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MLG BRAKE PRESSURE: TAXIING OUT, THERE WAS AN ABNORMAL AND VERY PRONOUNCED SHUTTERING OF THE BRAKES AS IF WE WERE ON ICE SKIDDING. WE STARTED TAXIING BACK TO THE FBO THEN THE LEAD PAX NOTICED ALSO AND ASKED IF THE BRAKES WERE OK. CORRECTIVE ACTION: PERFORMED TAXI CHECKS. NO DEFECTS NOTED. IAW PHENOM 300 AMM CH32-40-00 AND 32-43-05.