A healthy brake system is vital to the safety of the driver and its passengers. As this pertains to your BMW, it is also true for all vehicle brands on the road. Maintaining adequate brake pad thickness, clean brake fluid, and brake rotor condition will ensure the repeatability of your braking performance and confidence in all road conditions.
BMW’s built after ~1980 include a brake pad wear sensor on the front and rear axles. When the brake pad wears to a certain thickness, the sensor in the pad will rub through on the rotor and send a signal to the instrument cluster or infotainment screen, prompting the driver to service the brake pads and rotors.
As your brake pads wear to the recommended point of replacement, you may begin to hear a squeal or screech when you apply the brakes. This noise will inevitably turn into a grinding noise if not repaired. This grinding means the pad material has worn through to the pad “base”.
As the brake pads become thin from wear, the piston inside the caliper travels further out to provide clamping force on the rotor. This could be perceived as a brake fluid leak, but it generally signifies brake pad wear. If you experience a vibration in the steering wheel as you apply the brake pedal, this points to warped rotors and will require rotor replacement.
As mentioned above, the integration of a wear sensor in the brake pads will alert the driver about needing brake service. This message comes on well before the brake pads are at an unsafe thickness or level, allowing for preventative repair.
When the time comes for brake service, the rotors must also be replaced with the new pads, along with new wear sensors. BMW and most German auto makers manufacture the rotors to a point where they cannot be turned or cut as they wear, or during brake pad replacement. This is most likely an effort to minimize weight. A minimum thickness spec is stamped on each BMW rotor. In our experience, this minimum thickness is usually reached when it has come time for pad replacement, requiring the replacement of each rotor.
It is imperative to use OEM brake components on your BMW during replacement. Cheaper brake pads and rotors will not offer longevity between service and can offer a less than ideal performing brake system. Make sure your BMW repair facility is using OEM quality components when performing the service.
Bringing your BMW to the dealership will ensure you have the correct brake components replaced, but will come at a very high price tag. An independent BMW facility like SL Autoworks, will perform these brake services with equal or better quality components, but at a much more reasonable cost.