As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
L BLEED DUCT LEAK CAUTION MSG AND LEFT DUCT LEAK LIGHT DISPLAYED AT CRUISE POWER. RETURN TO SFO(<P>PER FIM 26-18-FT804. AT A/C ARRIVAL FOUND P61 PANEL LOOP SW SELECTED TO #1 POSITIONED TO LOOP #2 RAN ENG AT HIGH POWER WITH NO FAULTS. MDDR 86884 REMAINS OPEN.REF ITEM 3 - PER AMM 36-11-00-795-148 VISUALLY INSPECTED LH DUCT LEADING EDGE & #1 ENG STRUT FOR LEAKEAGE. NO DISCREPENCYS FOUND. OK FOR SERVICE</P>)