The official notice
Defect
On certain vehicles, corrosion could cause the brake booster to fail. If this happens, there may be an increase in brake pedal effort and increase the distance needed to stop the vehicle. In rare cases of severe corrosion, the brake booster could separate completely and cause a loss of brakes.
Safety Risk
A loss of brakes can increase the risk of a crash.
Remedy
Mercedes-Benz advises you to stop driving your vehicle immediately. The company will notify owners by mail and instruct you to contact a local Mercedes-Benz dealership to arrange for towing and an inspection. The dealer will remove the rubber brake booster sleeve and determine whether the vehicle is safe to drive or if it can't be driven and a parts replacement is necessary. Also, depending on the results of the inspection, you may need to return within two years for a re-inspection.