Before setting up a new car, always check where the position of the throttle goes in case signal gets lost or in case your TX suddenly turns off, loses power, etc.  Mine went to full throttle - a bad thing because the car takes off like a rocket with no control!  To set the brake fail safe, put something in the TX to push the trigger  forward. Then, push the RX fail safe button until you get blinks and then a return to solid.  Test again. Now you're set.  I made this video because my radio did not come with a manual. Hope this helps.