BMW brakes, as with any vehicle are one of the most important safety systems in your ultimate driving machine! Without brakes that are in good working order, you are putting yourself and those around you in a dangerous position. Brake pads are a wear-item that require replacement regularly, you can bet that we get a lot of questions about brake pads. Here are some common questions that you might have about the brakes for your BMW vehicle and some information to help you better understand the answers.
What is a brake pad?
Brake pads are essentially a metal backing plate that has a layer of friction material bonded to the surface that faces the disc brake rotor. As you drive, the pads remain stationary inside the brake caliper (seen here in red). There is an inner and outer brake pad that sit on either side of the brake rotor/disc as it spins. When the brake pedal is depressed, a hydraulic cylinder applies pressure to the brake fluid that runs to all of the brake calipers. That hydraulic pressure is converted into a mechanical force by the brake caliper that pushes both pads inward to contact the rotor and essentially squeeze the brake rotor/disc tightly which is what slows and stops the vehicle.
What causes the brake pad to wear on my BMW?
The brake pads don't really contact the rotor when they are not in use as you drive (although they look like they might be in direct contact with the rotor, they only touch and apply pressure when you step on the brake pedal). The friction of the rotor/brake disc spinning while the pads are pressurized against it as it slows the load and weight of the vehicle moving forward is what causes the brake pads to wear.
What kind of friction compound materials are used in BMW brakes?
BMW brake pad friction material as with most manufacturers comes in multiple types/compounds, such as metallic, semi-metallic, and ceramic. You can even get extra fancy on some of the BMW Motorsport vehicles that offer a Carbon-Ceramic braking system for extreme performance. Many BMW vehicles have a few different brake system options depending on the design of the particular car. BMW sport brake options are available for many BMW vehicles. Here at Driven SD we typically suggest sticking with the genuine BMW original equipment pads that came on your vehicle but if you do have a desire to change the pad material or upgrade to more of a performance-oriented pad, we can usually provide options for that as well. Some of our customers are less worried about peak performance and are looking for a brake pad that works well but puts out less brake dust to keep the wheels of the car clean, that is certainly an option too. Driven SD has the ability to meet whatever needs you might have when it comes to choosing the right brake pads for your car.
If the brake pads are the main wear material, why would the rotors need to be replaced too?
The brake rotors (also referred to as brake discs) are a hard metal disc that rotates with the wheels of your BMW. The discs are a much harder material than the brake pad surfaces but they do wear slowly over time as well. As the brake pads grasp the spinning rotor, it is normal for them to wear over time. The rotors will typically start to show some signs of wear at the outer edges of the disc where the pad does not quite reach. Rotor thickness can be measured with a special tool and that thickness is then compared to the minimum thickness spec that BMW has stamped onto the rotor hub. If the rotor thickness is not above that specified thickness at the time of brake pad replacement, the rotors would require replacement as well. BMW brake vibrations can also be a concern, if you are feeling a pulsation/vibration when you are depressing the brake pedal, that is a common indication of a warped brake rotor that might need to be replaced. There are a couple of other things that can cause a vibration that feels like this though, we suggest a brake inspection or vibration diagnosis if you're experiencing a brake vibration.
How long do BMW brake pads last?
That is a difficult question, there are so many different brake compounds on BMW vehicles and each vehicle platform certainly has a wide scale of braking needs/braking performance. The customers driving habits/driving style are a significant factor in the life expectancy of your brake pads as well. I would say that on average, BMW brake pads typically last an average of 30,000-50,000 miles but there are many exceptions to that statement. Some of the newer BMW models with the new brake pad compound can burn through a set of brake pads in less than 10,000 miles (which we do agree is a little crazy, but we have seen it happen).
How do I know if my BMW brake pads need to be replaced?
Driven SD offers a courtesy brake inspection at no cost. We'd be happy to check your brakes and let you know what condition they are in. For many years now, BMW vehicles have been built with brake pad sensors that will notify the driver when the pads reach the minimum thickness and that system does work well most of the time, but we are certainly here to take a look anytime you have questions about your brakes.
How much does it cost to replace BMW brakes?
That is another question that can vary widely. Every model is different, every model might also have a few different brake options on that particular car. The best way to answer this question is to contact Driven SD with your VIN number and we can price out the brake replacement job that is right for you and your BMW. That courtesy brake inspection we mentioned before is a great way to get the peace of mind you're looking for too. You can call us for a quote, use the submission form on our website, or stop by Driven SD and we'll discuss options to get your brake needs/desires handled properly at a fair price.
Check out some of our other articles related to BMW repair that you might enjoy, like "BMW Autohaus or BMW Werkstatt" and "BMW Spark Plug Replacement Guide"