The Mercedes-Benz disc brake pads are the disposable components of this braking system. There are two disc brake pads mounted in each caliper on your vehicle. The reason the disc brake pads are considered disposable is because it is their task to become worn when they are being used by the driver to stop or slow down their Mercedes-Benz. The wearing down of the pad is possible because they are constructed from a material that is softer by nature than the hard metal surface on the disc they come in contact with. This way neither of these braking components is damaged when the friction to stop the vehicle is being created. The pressure that pushes the disc brake pads against the rotor surface is supplied from the brake calipers on your vehicle. The inner pad is the one where the force is applied while the outer on is forced against the discs by the way the caliper is constructed. As these pads wear, the piston moves out which consumes an amount of hydraulic fluid. This lowers the level of the brake fluid in the corresponding reservoir in the brake master cylinder. By observing this level, the Mercedes-Benz owner will be aware of when a brake job will become necessary on their vehicle before any damage can occur. The Mercedes-Benz disc brake pads can damage the surface of the brake disc when they become totally worn out and only the backing plate remains in the caliper. The backing plate is made of a hard metal just like the disc, and when they make contact with each other a grinding sound will begin to emanate from the wheels when the brakes are being applied. To prevent this, the fluid level in the master cylinder should be looked at so the disc brake pads on your Mercedes-Benz can be replaced before they totally wear out.