As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BURNING RUBBER SMELL @ ROW 1/2 & IN COCKPIT GASPER VENTS. QRH 8.6 PROCEDURE ACCOMPLISHED AND SMELL DISSIPATED. NO SMOKE VISABLE IN CABIN OR COCKPIT. SMELL DID NOT DISSIPATE UNTIL RECIRC FANS SELECTED OFF. FOUND HYDRAULIC RESERVOIRS OVER SERVICED. SERVICED HYDRAULICS TO PROPER LEVEL AND REPLACED RECIRCULTAION FANS. (LP 7433390)