What was found
WHILE AIRCRAFT WAS IN HEAVY CHECK MAINTENANCE FOUND THE FORWARD LOWER SEAL DEPRESSOR AFT CARGO DOOR CORRODED. MAINTENANCE REMOVED AND REPLACED FORWARD LOWER SEAL DEPRESSOR AFT CARGO DOOR IAW EMB 170 SRM 51-40-02, 51-41-01, 51-21-02, AND AMM 20-10-01. THE AIRCRAFT IS OUT OF SERVICE IN HEAVY CHECK.