What is Brake Fade? Recognize the Causes and How to Prevent It
The car braking system plays an important role in maintaining safety while driving. However, continuous use of the brakes, especially when going downhill or repeatedly braking at high speeds, can reduce the brakes' ability to slow down the vehicle. This condition is known as brake fade.
Brake fade needs to be watched out for because it can make the car require a longer stopping distance than usual. To keep the braking system working optimally, drivers need to understand the causes, signs, and ways to prevent brake fade, especially when driving on mountain roads or carrying a full load.
What is Brake Fade?
Brake fade is a condition when the braking ability of a car decreases due to excessive heat in the braking system. Under normal conditions, brake pads generate friction against the surface of the disc or drum to reduce wheel speed. This friction process converts the vehicle's kinetic energy into heat energy.
When braking is done repeatedly or continuously, the heat generated can accumulate faster than the braking system's ability to dissipate it. As a result, the temperature of the braking components increases and braking effectiveness can decrease. Research published by SAE International in 2020 explains that repeated or prolonged braking at high speeds can raise disc temperatures to the point of causing brake fade.
This condition is different from brake failure, although both are equally dangerous. In brake fade, braking ability decreases due to heat, while brake failure is a general term for a condition when the braking system fails to work as it should. Brake failure can be caused by various issues, including brake fluid leaks or hydraulic component damage.
What Causes Brake Fade in Cars?
Brake fade is generally related to excessively high temperatures in the braking system. Here are some conditions that can increase its risk.
1. Braking Too Often on Downhill Roads
One common cause of brake fade is the habit of continuously pressing the brake pedal when going down a long hill.
As the car moves downhill, gravity helps the vehicle to continue moving. The driver needs to reduce speed by utilizing the braking system. If the brake pedal is continuously pressed to hold back the car's speed, the brake pads and discs will generate heat continuously.
If the heat is not allowed to dissipate, the temperature of the brake components can rise, reducing braking effectiveness. This risk is even greater if the driver is carrying a heavy load or going down a long slope at high speeds.
2. Repeated Braking at High Speeds
Braking from high speeds requires more energy to be converted into heat. If the car performs repeated braking in a short time, the temperature of the discs and brake pads can rise quickly.
If the braking system has not had time to dissipate the heat from previous braking, the next braking will add thermal load to the same components.
3. Incorrect or Worn Brake Pads
Brake pads have friction materials designed to work within a certain temperature range. When the temperature is too high, the friction characteristics of the material can change, reducing the pads' ability to slow down the disc or drum.
Worn brake pads also need to be checked because the thickness of the friction material decreases, and their ability to meet braking needs should not be assumed to still be optimal. Additionally, it is recommended to use brake pad brands recommended by Daihatsu manufacturers.
4. Brake Fluid Quality Degradation
In a hydraulic braking system, pressure from the pedal is transmitted through the brake fluid to the braking mechanism at the wheels. The brake fluid must maintain its characteristics within the operational temperature range of the system.
Brake fluid that has absorbed moisture can experience a decrease in boiling point. When the temperature rises too high, the brake fluid risks boiling and forming vapor bubbles. Because vapor is more easily compressed than liquid, hydraulic pressure can decrease, making the brake pedal feel deeper or spongy.
This condition is often associated with fluid fade, which is a decrease in braking ability due to thermal issues in the brake fluid. Its mechanism is different from the decrease in friction force on the brake pads, but both can occur due to excessive heat.
That is why checking the condition of the brake fluid and replacing it according to the vehicle maintenance schedule should not be overlooked.
5. Suboptimal Braking System
Braking performance is also affected by the condition of the discs, drums, calipers, pistons, brake hoses, and other supporting components.
For example, a stuck caliper can cause the pads to continuously rub against the disc even when the brake pedal is not pressed. Continuous friction can generate excessive heat and accelerate component wear.
Damaged discs or pads contaminated with oil or grease can also disrupt braking performance. Therefore, a decrease in braking ability should not be immediately assumed to be brake fade without further inspection.
What Are the Symptoms of Brake Fade?
Recognizing changes in brake behavior can help drivers take action before the situation becomes more dangerous. Some symptoms to watch out for include:
- Decreased braking power.
The car feels harder to slow down even when the brake pedal is pressed with normal pressure. - Increased stopping distance.
The vehicle requires a longer distance to reduce speed or stop. - Brake pedal feels different.
The pedal may feel deeper or spongy if there are issues with the brake fluid or hydraulic system. However, this symptom does not always appear in brake fade due to pads. - Burning smell from the wheel area.
The smell of overheated brake material may appear after heavy braking. This smell is a sign to stop using the brakes excessively and check their condition. - Smoke coming from the wheel area.
Smoke is a sign of heat or a serious problem that requires immediate attention.
These symptoms do not always indicate the same cause. If the brakes feel weak, do not wait for a smell or smoke to perform an inspection.
