What was found
KSJC - THE CREW REPORTED THAT WHILE THEY WERE TAXIING THE AIRCRAFT IN KSJC, THE LEFT BRAKE DEGRADED FROM POOR TO NIL. BRAKING ON THE RIGHT SIDE WAS NORMAL. MAINTENANCE BLED AIR FROM BOTH BRAKING SYSTEMS, AND PERFORMED AN OPERATIONAL CHECK. NO DEFECTS WERE NOTED, AND THE AIRCRAFT WAS RETURNED TO SERVICE.