Park the Mercedes-Benz on a level surface. Jack up the car and remove the rear wheels.
Remove the metal clip using a flat head screwdriver. Push the bracket towards the front of the car to remove it.
Locate the two bolts that secure the caliper on the bracket. Two small caps need to be removed to see the bolts. Once you remove the bolts, you will notice the caliper bolts. These are either T40 or T45 bolts. On some models, a 10mm Allen wrench is required.
Push the piston into the brake caliper using a brake pad spreader. If your Mercedes-Benz has electronic parking brakes, you will need to place the rear brakes in service position via the instrument cluster. If you don't have a brake spreader, use a flat head screwdriver to push the piston in, as shown in the picture below. Removing the brake reservoir cap under the engine bay will make it easier to push the piston back into the caliper. If your Mercedes-Benz has electronic parking brakes, you will need to put the rear brakes in the service position. You do this using the buttons on your steering wheel. See the owner's manual or look up our guide on "How to release Mercedes Electric Parking Brake Youcanic."
If you are changing the rotors, remove the two 18 mm bolts that secure the rear wheel assembly's bracket.
Remove the T30 screw from the rotor. Release the rear parking brake. Once you remove the screw, you can remove the rotor. If the rotor is rusted, it may be difficult to remove. If that is the case, use penetrating fluid and settle for at least ten minutes. Use a rubber mallet to push the old rotor out. Make sure the vehicle is secure and will not roll.
Clean the rear hub and bracket from any debris or rust. Install the new Mercedes rear disk. Install rotor securing bolt.
Install the bracket and torque the 18mm bolts to specification.
Install the new Mercedes wear brake sensor on the new pads. You can reuse old wear sensors if the sensor wires are not exposed. If the brake pad wear sensor wires are exposed or had a warning on your instrument cluster stating "Brake pad wear," you will need a new sensor.
Install new Mercedes rear brake pads. DO NOT APPLY GREASE OR ANTI-SQUEAL PASTE ON THE SURFACE BETWEEN THE PAD AND ROTOR.
Rember to apply anti-squeal grease to the brake pads' back and at the area where the brake pads slide on the bracket. Apply grease to the guide pins. Slide the caliper on the bracket.
Tighten the guide pins to specification. The typical torque range is between 30 and 55 Nm and varies between models. Call your dealer to get the recommended torque specifications for your Mercedes-Benz.
Connect the brake pad wear sensor. Install the tire and torque the lug nuts.
If you disconnected the SBC pump, reconnect it at this time. Start your car and press the brake pedal a few times until the pedal becomes hard to press.
Check the brake fluid and take your Mercedes-Benz for a test drive.
If your Mercedes-Benz has an SBC brake system (common on early E-Class W211 and CLS models), it should be disabled before you work on the brake system.
Alternative method: You can disconnect the SBC brakes by unplugging the wire harness to the ABS pump. The brakes defective warning will show up on the instrument cluster, but it will turn off once the ABS pump is connected. By disconnecting your SBC pump using this method, a fault code will be stored in the ABS or SBC control unit but reset once the ABS pump is reconnected.
Keeping SBC Active: If you decide not to disconnect the SBC pump, avoid opening any car door or lock/unlocking the car because the brakes will automatically apply. Be extremely careful when working on the brakes. If the SBC pump is activated when the caliper is removed, it will press the piston and brake pads, possibly causing injuries.