As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER T/O, LEFT ENG BLEED OFF EICAS MESSAGE. A/C RETURN TO ATL. MTC REPLACED HPSOV AND PNEU PRESSURE LINE FROM BRACKET DISCO, HPSOV NEED LEAK CHECK AND OP CHECK. PERFORMED LEAK CHECK, ENGINE AIR SUPPLY OP TEST PER MM 36-10-00-700-801. FOUND PNEUMATIC LINE TO PRSOV LEAKING WHILE PERFORMING LEAK CHECK. REPLACED UNION AT PRSOV AND RE-PERFORMED LEAK CHECK. LEAK PAST AND ENG AIR SUPPLY OP TEST PAST.