As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD - FLT 4076 - CAPTAIN NOTICED LEFT MAIN FELT SPONGY AND STOPPED AIRCRAFT. MAINTENANCE INSPECTED LEFT MAIN AND DECIDED TO TAXI AIRCRAFT BACK TO GATE. SPARKS STARTED COMING FROM NR 1 BRAKE, AIRCRAFT WAS PARKED OUT AT PENALTY BOX. CHANGED NR 1 BRAKE. NO FURTHER DEFECTS NOTED. AIRCRAFT WAS RETURNED TO SERVICE. (M)