As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: BRAKES ARE SPONGY AND WILL SUDDENLY GRAB WITH APPROXIMATELY DOUBLE THE EXPECTED BRAKING FORCE. MAINTENANCE NOTED THAT THE FIRST OFFICERS RUDDER / BRAKE PEDALS WOULD NOT ADJUST AND FOUND THE ADJUSTMENT HANDLE CABLE DISCONNECTED AND FRAYED. MAINTENANCE REPLACED THE PEDAL ADJUSTER ASSEMBLY CABLE PER AMM 27-21-43-002-A.