After graduating from Handelsschule (business school), Brachmann pursued commercial education.

From 1982 to 1985 he attended evening classes after high school and subsequently studied at the Sozialakademie Dortmund.

From 2001 to 2009, he was one of the alternating directors of the Medizinischen Dienst der Krankenkassen (MDK) in Lower Saxony.

In the Bundestagswahl 2013 he ran again in the Helmstedt-Wolfsburg electoral district retained his membership in the Bundestag.

He has been a trade unionist since 1971, first at the Gewerkschaft Handel, Banken und Versicherungen (HBV) (now part of ver.di).