It´s properbly the Idle Air Control Valve, it´s possible to clean it but that means taking it apart. I´ve tried it and it worked okay for me. It really has nothing to do with the brakes, the valve does not close itself like it should(because of dirt) when you ease on the gaspedal.
try visiting www.dervman.com
on the sidebar is a link called "-need Ka help?"
click that one and search for "erratic idle" somewhere down the page.
That´s the info that helped me with my car.
Good luck.
thitherikhansson@gmail.com
August 2007