brake pedal kicking back

so when you go to stop the car it pushes the break pedal back to you. could be a bent rotar if you also get shaking with it but more then likely it is the ABS motor pushing fluid back to the master and pushing your foot back. if you havnt driven the car in a while it could just bee it needs to adjust but if it keeps doing it to you you might need to take it to a shop and have them inspect the ABS unit. before you go that rough though try disconecting the ABS unit and then pluging it back in after a cupple miles. here is a video on how to find it https://www.youtube.com/watch? v=M5gxyfGQD7w