As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB THE FLIGHT CREW GOT A BLEED LEAK MESSAGE ON EICAS. AIRCRAFT RETURNED TO ORD. MAINTENANCE INSPECTED AND DEFERRED PACK NR 2 PER MEL 21-51-00-1. CLEARED NR 1 PACK MEL 21-51-00-1. SWAPPED NR 1 & NR 2 PACK OVERPRESSURE SWITCHES. SYSTEM OPS CHECKED GOOD.