How Do Brakes Fail?
Cars start, and they stop. As drivers, we need both of these features as much as we need to breathe in and out. If you’ve ever been in a vehicle that did not stop, you know the sheer terror that brake failure can cause. Whether your vehicle is equipped with disc or drum brakes, you expect them to work when you hit the brake pedal.
Brakes can’t talk — or can they? If you’re not distracted with chatter or music, you might hear your brakes trying to tell you when something’s wrong. Brakes have their own language; they squeal, click, squeak and grind. Read more about diagnosing brake noises in this blog. You need to listen carefully to their noises rather than ignore them and hope the sounds will magically disappear.
The easiest way you can avoid brake failure is by maintaining the vehicle regularly and being attentive to any changes in performance. Because a vehicle’s brake system involves many components along the entire length of the vehicle, any number of things can go wrong. Callipers, drums, and brake pads.
In a perfect world, maintenance will eradicate brake failures. However, if you’ve kept to your end of the bargain and the brakes begin to fail, what dangers might you and your passengers face, and how can you prepare for them? What will you do if you are towing and experience brake failure?
Brake Failure Causes
Functioning brakes stop a vehicle by using friction. In this way, they are unlike the engine, which must always be kept lubricated to run smoothly. In front brakes, friction stops the brake callipers and pads. In rear brakes, friction hits the brake drums and shoes.
Several factors can interfere with this friction and lead to brake failure:
- Grease or oil on brakes causes brake failure, because it interferes with friction. If oil leaks, it may indicate that an oil seal has failed.
- When the brakes overheat to a great degree, the metal in the brake rotors or drums develops hard spots. These are known as hot spots. The hot spots resist the friction from the brake shoes and pads. Because the shoes or pads have nothing they can grasp, there’s no friction. Consequently, braking power is lost.
- Brakes that squeal indicate that the brake pads are wearing thin. By the time the brakes begin making a grinding sound, they’ve worn down past the pads to the rotors, which will cost more than pads to replace.
Do you know anyone who nervously “rides the brake” when driving? How about the “quick-stop specialist” driver who often stops in a panicked way? This type of driver is headed for crystallized brake pads or shoes. Because of the heat generated over repeated overuse of the brake, the pads and the shoes grow hard and are ineffective. Brake material has to be flexible and able to grasp the disc or drum in order to stop the vehicle.