"Minas Geraes" was modernized at the Rio de Janeiro Naval Yard from June 1931 to 1938, while "São Paulo" led a naval force that blockaded Santos during the Constitutionalist Revolution of 1932. Though Brazil had also intended to modernize "São Paulo", its poor condition—she was only able to make instead of its designed speed of —made such action uneconomical. Soon after Brazil's entrance into the Second World War on 21 August 1942, "São Paulo" was moved to Recife on 23 August to defend that port as a harbor defense ship; "Minas Geraes" played a similar role at Salvador. Even with the modernization, "Minas Geraes" was simply too old and vulnerable to actively participate in the war.