What does a "soft pedal" indicate during braking?

A "soft pedal" during braking typically indicates that there may be potential air in the brake lines. When air infiltrates the hydraulic system, it creates compressibility in the brake fluid, which results in a spongy or soft feeling when the brake pedal is pressed. This condition can significantly reduce the effectiveness of the braking system, as the air bubbles do not transmit the hydraulic force as efficiently as brake fluid does. Consequently, the driver may experience a lack of braking power or delayed response when applying the brakes.

In contrast, the other choices do not align with the characteristics of a soft pedal. High braking power would manifest as a firm pedal feel with an immediate response; normal operation indicates that the brake system is functioning properly, typically signified by a firm pedal; and excessive brake fluid might lead to other issues, but it would not usually present as a soft pedal feel. Understanding the implications of a soft pedal is crucial for diagnosing brake system problems, maintaining safety, and ensuring the vehicle responds appropriately during braking.