As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SFO ON GROUND T1951/07JUL - AFTER LANDING FLIGHT ATTENDANTS REPORTED SMOKE IN CABIN. TURNED OFF APU BLEED AIR AND SMOKE BEGAN TO DISSIPATE. FOUND THRUST REVERSER HYDRAULIC LEAK AT CONTROL VALVE B NUT. TIGHTENED NUT AND NO LEAKS FOUND. REPLACED APU DUE TO HYDRAULIC FLUID INGESTION. SYSTEM GROUND CHECKED NORMAL OPERATION.