What are the reasons for sudden brake failure when driving downhill?

[LeRonan]

There are several reasons for sudden brake failure when driving downhill: 1. Wear of brake pads and brake discs: The wear of brake pads and brake discs leads to thinning of their thickness. For example, in disc brakes, the caliper clamps the brake disc for braking over a long period of time. Over time, friction causes the surfaces of the caliper and brake disc to become thinner, which increases the travel distance of the brake pedal. 2. Issues with brake fluid: Most vehicles use hydraulic braking systems, which require brake fluid to pressurize and transmit braking force to the brake pads. 3. Tire wear: The lifespan of tires is generally around 60,000 kilometers. As tires approach the end of their lifespan, the tread becomes very thin, and the adhesion between the long-term friction-worn tires and the road surface deteriorates, leading to an increase in braking distance.

[EdenMarie]

I have driven in mountainous areas for decades and encountered sudden brake failure on downhill slopes several times. Common causes include brake fluid leakage leading to insufficient hydraulic system pressure; or frequent braking on downhill slopes causing overheating and fade of friction pads; blocked or ruptured brake lines are also common issues; air intrusion into the brake system causing vapor lock; and poorly maintained vehicles with excessively worn friction pads can also lead to failure. I recommend car owners check brake fluid levels before long trips, avoid continuous braking on steep slopes, and use engine braking to assist in reducing risks. Regular maintenance can effectively prevent these troubles, especially for older cars, which have greater hidden dangers—safety should always come first. Driving requires caution, as lives are at stake.

[LeGavin]

As a parent who frequently travels with children, brake failure is truly nerve-wracking. Possible causes include insufficient or leaking brake fluid, overheating and fading of brake discs, aging and clogging of pipelines, excessive wear of friction pads, or errors caused by improper modifications. When temperatures are too high, the hydraulic system may fail, making continuous braking on downhill slopes particularly dangerous. If encountering such a situation, stay calm and try downshifting to use engine braking or gently apply the handbrake to control speed. I always remind myself to regularly replace brake fluid and check the thickness of friction pads, as family safety comes first, and prevention is better than cure. Making it a habit to inspect the braking system before driving can significantly reduce risks, especially on mountain roads.

[SanHannah]

Common causes include brake fluid leakage or low level, brake fade due to overheated friction materials, blocked or ruptured brake lines, air in the system, and excessive wear of friction materials. In case of brake failure during downhill driving, remain calm and immediately use engine braking or downshifting to assist in slowing down. It is recommended to regularly maintain the braking system to prevent further damage. Pay attention to driving safety and address issues promptly.