Rusty brake nuts & cables: Should I change my brakes or not? I have been using a used bike for a few months now and when I bought it it was in mint conditions. However, the winter has been really harsh were I live and since I drove every day to work with it some components have become rusty (even though I cleaned and greased everything upon me buying it). What worries me the most are the brakes. They are simple rim brakes attached with one long bolt to the bike frame. Almost every nut on them has become rusty and the cables have quite a lot of rust on them too. On the other end, the body of the brakes is clean and there is no rust on it.

Now I was wondering whether I should just get new brakes or maybe change nuts, bolts and cables. I saw that this latter is not really cost efficient where I leave, so maybe changing everything is not a bad idea afterall. But is it necessary? What do you think?
Surface corrosion on nuts and bolts isn't a safety issue, so you don't have to replace the brake calipers. As David D suggests you can clan this off with steel wool. I would carefully apply a thin coat of grease as I spraying WD-40 on bikes attracts crud and you certainly do not want to get it on rims or brake pads.

Rusted cables is another matter. If the cable is rusted the housing probably is too. The corrosion may impede the travel of the cable through the housing and affect braking performance. I'd replace the cables at least with good quality stainless steel ones. They are not too expensive. You probably should have a look at your shift cables too.