When driving a car or any other vehicle, the ability to stop precisely when and where you want is paramount to safety. Not only that of yourself but of the other road users as well. What makes the car reduce its speed and eventually come to a complete halt is the friction of tyres against the road's surface.
This task wouldn't be so easy without the brakes. After all, wheels are never enough to do that and producers design their modern products to cause as little rolling resistance as possible to optimise cars' fuel economy. Vehicles, therefore, rely on a braking system to function without fail.
How do brakes work?
Whether they are drums or discs, brake systems stop the car by generating friction and, as a result, slowing down the vehicle until it eventually stops. Unfortunately, this stopping power is also responsible for immense heat that is a by-product of this process. Even though brakes can resist high temperatures, they are not immune to heat damage. When we use them very often, that hotness might be too much for them. Some discs and callipers can even withstand temperatures of over 600 degrees Celsius. And that is enough heat to melt aluminium. However, when we press on the brakes too often and don't let go for a long time, we give them little time to dissipate that heat. And that is precisely what causes the phenomenon of brake fade.
Brake fade definition
Braking system fade or brake fade is just another name for the reduction of the vehicle's stopping ability. It occurs most often when we are driving down a long slope. By constantly pressing on the brakes to control the speed, rather than doing it using engine braking, we gradually lose stopping power.
Brake failures are the leading cause of accidents in the UK. 2019 research, covering the period between 2013 and 2018, defective brakes were responsible for nearly 4.000 serious crashes that resulted in serious injuries or fatalities.
So, what are the dominant causes of brake fade?
- Friction fade due to the buildup of heat is the number one culprit. Drums, discs and callipers fail when overheated, and drivers can feel that spongy sensation almost immediately.
- Brake fluid fade is also a common cause. It happens most often in the case of old cars, whose owners forget or choose to forget to change brake fluid. The old fluid absorbs water and dirt, becoming less and less effective in withstanding heat.
- Mechanical fade happens much less often. Still, it is good to know that after replacing the brake pads, we shouldn't put them to work too much. That is because they have some resin that breaks down and produces gasses, which can reduce friction.
How can brake fade be avoided?
First of all, by responsible driving. Speeding means that we have to brake very often and, unless we own a performance car, our brake system wasn't really meant for that. We should also utilise engine braking when going down long hills to give the discs and drums some time to cool. The proper brake fluid is also paramount, and it's good to replace it every year with our annual service to make sure it always stays clean.
What to do when you experience brake fade?
If you need to halt abruptly, slam on your brakes but only to find out that your car doesn't stop right away, don't panic. Keeping your cool is the best thing you can do to avoid an accident.
First of all, start downshifting. Put your car in a lower gear immediately. You can even skip one for better effects and then release the clutch. Don't worry if your vehicle jerks, as this emergency braking is all about safety, not comfort.
At the same time, you can also use a handbrake to slow the car down. You have to be careful, though. When you overuse it, you might lose control of your vehicle, so always be ready to let go.
Remember also not to touch the wheels after prolonged braking or experiencing brake fade on the road. They will be extremely hot and will burn you if you touch them. Let them cool down, and only then continue with your journey.
Prevention is better than the cure
Brake fade is a significant problem, and many motorists don't have the training and experience to handle it properly. It is, therefore, crucial to keep our vehicles in good shape and know how to drive down long slopes without putting too much strain on the braking system.
The ability to identify dangerous situations on the road is a good trait that every driver should have. It usually comes with experience, so those who don't drive too often or have just received their full driving license should be cautious. Most of the dangerous situations on the roads can be avoided by simply adjusting the speed to the conditions and thinking ahead.