What causes the brakes to overheat (and what to do if it happens) – Jalopnik

You probably won’t drive fast enough to cause your car’s brakes to overheat on the way to the grocery store or on a school run. But it’s a different matter on a track day, while towing and going downhill, or while driving fast on a winding road in the summer heat. Brakes can tolerate heat, and their components are designed to do just that. Higher temperatures are a byproduct of braking and arise from the friction required to steadily bring your jalopy to a stop.

Today’s braking systems are designed to withstand daily wear and tear, and the advent of disc brakes is the reason why most modern cars no longer use drums. Simply put, discs can dissipate heat better than drum brakes, but they aren’t immune to overheating either. Carrying heavy freight or towing extra cargo makes it harder to stop your car, putting more strain on your car’s braking system and increasing the chance of overheating. Braking on inclines while driving on scenic but dangerous mountain roads is also a surefire recipe for brake boilover.

It is important to note that vehicle maintenance and your driving habits contribute greatly to braking performance under duress. And while it’s not impossible to overheat the brakes when you’re stopping, going, and cornering like a professional racer (especially on a track day), worn brake pads and improper installation of brake components can also lead to overheating.

Meanwhile, faulty components can contribute to overheating. Corrosion and damaged seals cause the caliper to stick. When this happens, the caliper will not retract the brake pads from the rotors after the pedal is released. Since the brake pads are still touching the rotors, the situation generates more heat while driving, ultimately leading to rising temperatures in the system. If one or two wheels are too hot to touch after driving, you may be dealing with sticky brake calipers.

Furthermore, bad wheel bearings are not only noisy, but can also contribute to overheating and weak braking. Other possible causes of brake overheating include excessively worn brake pads and low brake fluid levels.

Although the brake pads and rotors can handle temperatures of about 250 degrees Fahrenheit to 300 degrees Fahrenheit (121 degrees Celsius to 149 degrees Celsius) during normal driving, braking while descending or driving too aggressively can increase brake temperatures to a scorching 600 degrees Fahrenheit to 700 degrees Fahrenheit (315 degrees Celsius to 371 degrees Celsius), which is enough to crystallize or glaze the friction-generating materials of the brake pads. Basically, the pads can be overcooked, which affects their friction-generating properties. This means you will no longer be able to stop, no matter how hard you press the brake pedal.

Other symptoms of overheating brakes include visible smoke, burning odors coming from behind the wheels, and some blue or purple discoloration on the rotors, all major indicators of hot brakes. Another noticeable symptom is vibration or pulsating sensations when pressing the brake pedal. These vibrations are usually caused by warped brake discs, which mainly occurs when the rotor surface develops imperfections due to, you guessed it, too much heat.

Then lift the hood, inspect the brake fluid level and add more fluid if necessary. Allow the brakes to cool for 10 to 15 minutes before setting off. If you can help it, avoid ignoring the symptoms of overheated brakes as this can lead to huge repair costs or total brake failure.

If you notice that your car or truck’s brakes are overheating quickly, it’s probably time to service the brakes and have the vehicle inspected by your favorite mechanic or garage as soon as possible. You may need new brake pads, rotors, or brake fluid flush. For reference, brake rotors can last 60,000 miles or more, while inspecting and replacing the brake pads every 20,000 to 60,000 miles ensures your anchors are in top condition when you need them most. It’s also worth upgrading your ride’s braking components if overheating problems persist. For example, drilled or slotted rotors have their pros and cons, but they can dramatically improve braking performance when paired with performance ceramic or semi-metallic brake pads.