How Do I Know if it's Time to Replace My Brakes?

Annie at Hawk Performance

03/25/2020

No matter how great they are new out of the box, brake pads and rotors are expendable components that wear away during everyday use. Their job involves lots of friction and very high temperatures, which leads to erosion over time. Damage resulting from overheating because of heavy braking, a poor fit, or excessive debris between the pad and rotor (just think of all that salt and sand on the roads all winter!) can accelerate that wear, and may considerably reduce the lifetime of your brake pads and rotors.

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Just How Do Brakes Work?

Most of the cars and trucks we drive on a daily basis these days have a disc brake system of some kind – either on the front and rear axles, or at least on the front axle. There are lots of moving parts to the entire brake system, but two major components – and the ones that wear out after constant use – are brake pads and brake rotors.

Rotors are metal discs, installed on the wheel hub, that rotate with the wheels when driving. Brake pads are installed in pairs inside calipers, and are made up of a steel backing plate and compressed friction material. When you step on your brake pedal, spring-loaded pistons in the caliper pushed the brake pads directly against the front and back of the rotor, squeezing it to stop the rotation of the wheels.

Depending on the force a driver uses on the brake pedal, the brake pads rub against the rotors to a greater or lesser degree. This force can be modulated by Active Safety Systems, such as an anti-locking braking system, but with or without ABS, this is how all disc brake-equipped cars brake.

Front brake pads and rotors usually wear out a little sooner than rears, as the engine or gearbox in the front of the car makes it more heavily loaded. This is why stronger and larger brake pads are fitted to that axle. Rear brake pads and rotors should wear out more slowly, however, brake pad and rotor replacement should include both units, at the front and rear axle as a whole set to ensure uniform wear on tires and even ride overall.

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What's the Service Life of Brakes?

High performance street brake pads and rotors may theoretically endure 25,000-30,000 miles and 50,000-75,000 miles, respectively. We say theoretically, because this life depends largely on your own personal driving style, what type of car or truck you have, the initial quality of the parts in your brake system, and many, many other factors. Are you a city driver who doesn’t get up to 65 mph very often, but does a lot of braking in stop and go traffic or at street lights? Are you a rural driver who uses your truck to haul large trailers and heavy payloads? Are you a road warrior who traverses up and down mountains regularly? All of these scenarios can present different challenges and wear to your brakes!

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But How Will I Know if My Brake Pads Are Really Worn Out?

Warning signals can range from really obvious to much more subtle, so let’s explore all the possible methods for checking the state of your brake pads.

  • Loads of cars and trucks are now equipped with electronic brake pad wear sensors. If the thickness of the brake pads is dangerously low, a warning message is displayed on the dashboard. You may think your brakes don’t feel any different, and they may very well be performing exactly as intended, so it’s tempting to ignore that little light when it pops up. Don’t do it!
  • Using your own ears is another surefire way to tell your brake system needs attention. Many cars use simple acoustic sensors, which are small pieces of metal installed next to the brake pad when they’re manufactured. If the thickness of the brake pads is getting low, these little metal bits start to rub against the rotors during braking, giving off a loud metallic squeal to grab your attention. Additionally, if you hear a metallic grinding, scratching or screeching noise when braking, that’s a red flag that your brakes need immediate attention, as the friction material on the brake pads themselves may be fully worn down or damaged. Again, it may feel like your brakes are working great, but don’t ignore your ears!
  • Your nose is another tool to employ. If you smell the characteristic odor of burnt asphalt during heavy braking situations or even your regular commute, it could be a sign that the friction material on your brake pads is charred. Reasons are many, but some common ones include prolonged braking (during mountain driving, for example), driving with constant pressure on the brake pedal, or caliper failure (a blocked piston causes the brake pad to keep rubbing on the rotor). Any of these situations can lead to wheel rims getting overheated, and to fuel consumption dramatically increasing.
  • You know how your car handles better than anyone, so if you feel it misbehaving in any way during braking, don’t ignore it! Veering to one side or another during braking, having to apply prolonged and noticeably longer pressure to the brake pedal, or feeling a shudder instead of a smooth deceleration are all warnings you need to heed. It could be that the pads on one side or axle of the car are wearing faster than the others, that they are wearing unevenly, or that one or more of them are experiencing a serious failure like the friction material breaking off completely from the steel plate.
  • Despite all of the components of your brake system being in good shape and working as they should, poor braking or no braking can happen if friction linings get covered in oil or fluids. Leaking fluid or solution lines from damaged wheel hubs or other parts of your vehicle can wreak havoc on your braking abilities, so make sure you give them adequate attention if you experience this.
  • And last but not least, if everything looks good and feels good, but you’ve reached that 50,000+ miles marker and are concerned about the shape of your brake system, taking your car into your local mechanic is another easy option. They can measure the brake pad friction material with a slide caliper. Simply put, if the friction material is too thin, your brake pads need replacing.

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Don't Ignore the Signs!

No matter how you determine it’s time to replace your brakes, it’s important to act promptly. Regardless of what their quality was when they were new, worn out brake pads should not be relied on to save you in high pressure braking situations. The added friction, heat, and pressure put on the fatigued pads when you slam on the brakes in an emergency can cause them to crack or even shatter the friction material.

Paying attention to what your car is telling you and changing your brake pads and rotors for new, high performance products guarantees your safety on the road today and down the road!