As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ETOPS SIGNIFICANT SYSTEM, LOW PRESS LIGHT ILLUM EICAS MSG DISPLAYED C HYD PRIM1. EICAS MSG C HYD SYS MAINT WAS NOT DISPLAYED. OPS CK CENTER HYD SYS COULD NOT DUPLICATE PROBLEM. REPLACED C1 ELECTRIC HYD PUMP PRESSURE SWITCH IAW MM 29-11-18. OPS AND LEAK CK OK IAW PRECAUTIONARY ACTION.