BMW bulletin B340714

"Carbon Ceramic Brake Noise. INFORMATION ""M"" vehicles are designed for high-performance, spirited driving. To accommodate this type of driving profile, a braking system which exceeds the standards for handling heavy brake forces, extreme temperatures, and excellent stopping power at high speeds is required. ""M"" vehicles can be ordered with the optional ultra high-performance braking system, featuring perforated carbon ceramic brake discs designed for circumstances similar to those encountered on racetracks. The carbon ceramic brakes were designed to improve braking efficiency, and dramatically increase braking performance along with a significant reduction in weight. When developing the carbon ceramic brake system, the main focus was on braking performance for the sporty-minded driver, while accepting the comfort limitations of functional noises at slower speeds and when coming to a stop. Please inform the customer that the carbon ceramic brake system's functional noises (squealing/honking), are a known characteristic for this type of material, and are only a small trade-off for the improved braking performance. These functional noises have no effect on the performance, operational reliability and durability of the brakes. Part replacement will not provide a remedy for the noise; this is a known characteristic of the high-performance brake system. More information on the performance and operation of these brakes can be found in the Owner's Manual under ""M carbon ceramic brake."" WARRANTY INFORMATION Not applicable."