I have a problem with my otherwise wonderful car. it is a 300c -07, and the brakes are pumping. The wheel is rattling and the brakepedal pumps rather heavily. Is it just to change the disques or what can the problem be?

 

The most likely cause of shuddering in the brake pedal is disk (rotor) runout. You might be able to solve the problem by having the rotors machined. A quality brake shop will have equipment to machine the rotors right on the car. If the rotors are worn too much, they will have to be replaced, which will also solve the problem. If you are handy with tools you can replace the rotors yourself. Replace the pads at the same time.