Alfa 156, Brake Problem?

[Berrimedia]

Heys guys, first post here and liking it so far! Was hoping a few of you could help me with my current problem. I own a 2002 Alfa 156 Selespeed Sport, and for the record, it is probably one of the most unreliable cars I have ever owned! But I love driving it hehe. Just came out of the shop to fix a shredded ball bearing in the gear box among other things which set me back $4500. Anyway, im having an issue at the moment, when I brake sharply/heavily, I can hear a loud, deep, humming noise. Im looking at selling the car in the near future and I dont want these obvious things to be on display. Can anyone help? Why am I hearing this noise?

Thanks guys!

[Romeo156]

damn we both exactly the same car. i hope i wont get that problem.. at the moment im having problem with a cat converter rattling and the brake just need a new set of rotors at the front