What was found
IAS DISAGREE AT FL380 RAN QRC QRH. RESULTED IN A RETURN TO GUM. CAPT SI DE WAS 15 KTS SPLIT. FLUSHED AND DEBRIS REMOVED FROM LEFT (CAPT'S) PITOT PROBE REF AMM 34-11-00-170-802 (ALTERNATE METHOD). PERFORMED LEFT PITOT LEAK TEST REF AMM 34-11-00-790-810. LEAK TEST PASSED. INSPECTED PITOT PROBE, NO OBVIOUS DEFECTS OR FAULTS. PITOT HEAT OPS CK GOOD. -END- CW IDT INSP ON CAPT'S ADM QD FITTING AND DRAIN QD PER AMM 34-11-00-170-802. PERFORMED LEFT PITOT LEAK TEST REF AMM 34-11-00-790-810