Brake rotors are the rotating discs on the Mercedes-Benz disc brake system. They are mounted on the Mercedes Benz drive train and provide a clamping surface for the brake pads. When you step on the brake pedal, the foot pressure is transmitted hydraulically by the master cylinder to a push rod connected to the caliper-driven brake pads. Depending on the foot pressure input, the caliper then squeezes on the brake rotors and retards the motion of the car.

The disc brake system of the Mercedes Benz works in principle like the brakes on a bicycle. But, since cars need more braking power, the caliper in the disc brake assembly clamps on the rotor to apply restraint on the wheels instead of a caliper tightening on the wheel itself. Aside from improved braking power, the Mercedes Benz disc brake assembly spares the wheels from the resulting friction.

Operationally, the brake rotors are exposed to high heat condition. Most Mercedes Benz brake rotors are made of cast iron to withstand the heat and friction against the brake pads. But the chronic contact between the two makes them highly disposed to regular replacement and maintenance. Brake pads are one of the maintenance items in a Mercedes Benz that require periodic replacement, while brake rotors often have a long service life.

Replacement brake pad sets are categorized as per drive applications. Brake pads with harder and less aggressive compounds are designed for Mercedes Benz cars used in city driving. Using this kind of friction material on performance cars can result in brake fade. Race cars, or performance Mercedes Benz cars for that matter, are fitted with a brake pad set lined with soft and more aggressive friction material like asbestos, Aramid, etc. Driving style and preferences are often valid considerations when deciding on brake pad replacement.

Because most brake pads are equipped with aggressive friction compounds, brake rotors are periodically flipped to make rotor wear even. However, turning the brake rotors can reduce their ability to temper heat in the high-friction operating condition. Heat buildup between the brake rotors and the brake pads can "warp" or reshape the brake rotors, causing thickness variations. When this happens, you get a pedal pulsation, and sometimes, a jolt in the steering wheel. When the brake rotors get worn over time, they do not only get thin but lose the heat ventilations on their contact surface. This ventilation exhausts friction heat via the holes that are cross-drilled on the discs.

Aftermarket Mercedes Benz brake rotors can have fins or drills hollowed out of them that are meant to dissipate heat at greater amounts, preventing rotor warping and brake pad wear. These usually go to the front brake rotors, which carry more of the weight load of the car and are faced more frequently by hard braking operations.

There are also slotted discs. This type can be the most ventilated brake rotor. However, slotted discs are more appropriate for Mercedes Benz earmarked for racing and hard drive applications. The slots on the brake rotors, while reducing considerably the possibility of heat buildup, can wear out the brake pads easily. They are nonetheless reliable in preventing the brake pad material to stick on the discs and reduce the braking power of the assembly. When looking for Mercedes brake rotors, these design considerations can let you do away with the largest of requiring premature replacements.