What to Do When Disc Brakes Fail to Stop the Vehicle?

[StOlivia]

The inability to stop could be due to excessively worn brake pads or aging/damaged brake cylinders, leading to issues like sticking or insufficient pressure causing oil leakage. Additionally, check if the brake fluid is insufficient or if the channels in the cylinder are clogged. It might be necessary to replace the brake cylinder.

[VonManuel]

Once on the highway, I suddenly felt the brakes were spongy and almost had an accident—it was really close. Disc brake failure might be caused by oil contamination or rust on the brake disc surface, so you should thoroughly clean the disc with alcohol first. Also, if the caliper piston gets stuck, it can reduce braking force, in which case you’ll need to disassemble and clean the caliper. If the brake pedal vibrates when pressed, there’s an 80% chance the brake disc is warped and needs replacement. Oh, and never overlook the brake fluid—over time, excessive water content can affect the entire system’s pressure. I’ve since made it a habit to change the brake fluid every two years. These are all lessons I’ve learned from driving trucks for 20 years. If you ever have brake issues, don’t hesitate—pull over immediately and call for help.

[JosephRose]

Last time, the mechanic taught me how to check the reasons for disc brake failure. Now I’ll share it: First, squeeze the brake lever to feel the pressure. If it’s particularly loose, it might be due to insufficient brake fluid or air in the system, requiring fluid top-up or bleeding. Then, squat down and check the brake pad thickness—replace them immediately if they’re below 3mm. Next, feel the brake disc temperature; a significant difference between the two sides indicates a caliper issue. I remember my old car had a slight brake fluid line leak causing low pressure, and it only returned to normal after the repair. Actually, most disc brake problems can be prevented in advance. It’s recommended to have the entire brake system inspected by a professional shop every 5,000 kilometers.

[MackenzieDella]

Brake failure is terrifying, and I've experienced it twice. The first time was right after washing the car when there was a water film on the brake discs, making the first few presses completely ineffective. The second time, I noticed the brake pads were worn so smooth they reflected light like a mirror, with the metal backing directly contacting the rotor, rendering braking impossible. Always listen for unusual noises while driving—those metallic scraping sounds are warning signs. Once after rain, my brakes failed because the pads were clogged with mud and sand. In emergencies, you can try using the handbrake for assistance, but only at low speeds. I recommend keeping a brake pad measuring caliper in the car and replacing the pads immediately when the wear indicators are gone.