As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT NR 6388 - IAD-PIT - DURING CRUISE, RETURNED TO IAD DUE TO THE LEFT HYDRAULIC PUMP FAILING. AIRCRAFT RETURNED TO IAD WITH NO FURTHER INCIDENTS. MAINTENANCE REPLACED THE HYDRAULIC PRESSURE SWITCH. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (M)