What was found
CLIMBING THROUGH 12000 FT MSL, RECEIVED A BLEED 2 LEAK EICAS, RAN CHECK LIST. BLEED ONE WAS ON MEL, RENDERING AIRCRAFT UNPRESSURIZED. DIVERTED. TROUBLESHOT PROBLEM TO A LEAKING PRECOOLER EXHAUST DUCT PANEL SEAL. REMOVED AND REPLACED THE SEAL IAW AMM 54-50-25.