You hit the brakes and nothing happens. What now?
First thing to do is stay calm. A cool head will allow you to take steps to control your car.
Second, take your foot off the accelerator and make sure the cruise control is disengaged. Regardless of whether your car has a manual or automatic transmission, you can usually engine-brake the vehicle by downshifting to a lower gear. Once it starts to slow, continue down through the gears as your speed decreases.
If the road surface is dry and you have successfully slowed the vehicle to less than 30mph, try using the parking brake. Remember, this is a separate braking system and should still work, although it is not nearly as powerful as your car’s regular brakes. Bring your car to a complete stop, off the road if possible, and turn on your emergency flashers. Have the car towed to a repair facility for inspection and repair.