You could experience loss of braking if __________.

Loss of braking can critically compromise vehicle safety, and one of the most severe causes is leaks in the hydraulic lines or hoses. The braking system operates on hydraulic pressure; when the driver presses the brake pedal, fluid is pushed through the hydraulic lines to engage the brake pads. If there are leaks in these lines or hoses, the hydraulic pressure decreases, which can lead to a complete failure to engage the brakes. This loss of fluid not only reduces braking effectiveness but can also lead to total brake failure, making it imperative to regularly check the integrity of the hydraulic system.

Worn-out brake pads can reduce braking effectiveness, but they do not lead to loss of braking entirely; rather, they may cause noise or increased stopping distances. Old brake fluid can cause performance issues over time, such as increased moisture content affecting braking performance, but it would not result in an immediate loss of braking. Malfunctioning brake lights, while indicative of possible electrical issues, do not impact the actual braking performance; they only affect the visibility of the vehicle's braking actions to others. Therefore, hydraulic leaks present the most direct threat to the ability to stop the vehicle effectively.