Final Answer:
You should know that your brakes are fading when the brake pedal feels spongy when you apply pressure. (Option b)
Step-by-step explanation:
Brake fading is a phenomenon that occurs when the braking system experiences a decrease in stopping power due to various factors, including overheating of the brake components. The specific indicator mentioned, a spongy feeling in the brake pedal, is a common sign of brake fade. When brakes overheat, the heat generated can lead to a reduction in the effectiveness of the brake fluid, causing it to boil. This results in air bubbles in the brake lines, leading to a spongy or soft feel in the brake pedal.
In practical terms, if you notice that you have to apply more force to the brake pedal than usual, and it feels less responsive or spongy, it could be an indication that your brakes are fading. This is a critical situation that requires immediate attention to prevent a potential loss of braking efficiency, which could compromise vehicle safety. It's advisable to address brake fading issues promptly by allowing the brakes to cool down, checking the brake fluid level, and, if necessary, seeking professional inspection and maintenance.
In summary, recognizing brake fade is crucial for maintaining safe driving conditions, and the spongy feel in the brake pedal serves as an important warning sign that requires prompt action to ensure optimal braking performance.(Option b)