Cars' rear brake??????????

Avis Brantner: they are in use everytime you push the brake to stop and the back brakes are used for the parking brake too.

Carmina Stickney: The rearing brakes are a part of your braking system. When you push on the petal, they get used the same time as your front ones.Normally, the front brakes make up 70% of the system, you can add more life to your fronts by setting your parking brake before you leave the vehicle. That allows the self adjusters in rear to more the shoes closer to the drums.

Leif Andreason: Well both answers have good arguments. It is true that cars dont use rear brakes at slow speeds or in traffic. Actually it is requiered to manufacturers that front brakes by themselves stop the car even under severe using conditions. Rear brakes are just to optimize braking and make the car safer. It depends mostly in the car's technological advances and safety features. On cars that have drum brakes, some have self-adjusters that keep the shoes close to! the drum but doesnt mean it brakes all the time. It has a point whether how much you've got your foot on the pedal that activates rear drums. On disc brakes is the same the only thing is that most are hydraulic and don't need a self-adjuster. Sports and racing cars use the rear brakes probably in a 60/40 ratio, which is around 10% more in the rear than normal city driving cars. Too much power on the rear brakes will make the car loose control on the rear and could get you in serious trouble when speeding, especially in the city....Show more

Sylvie Snetting: Rear brakes are used to lock the wheels and locking them would cause fish tailing instead of stopping it. Anyways they are used just like your front brakes. Your front brakes are bigger(generally) because weight shifts to the front of the car while braking. One exception to this is the Porsche 911 which has even brakes because its rear engined so on braking the cars weight is balanced 50/50.