2005 Mercedes C-Class Owner's Manual - Page 305

Practical hints What to do if ... Problem Possible cause (USA only) The red brake warning lamp comes on while driving and (Canada only) you hear a warning sound. The red brake warning lamp comes on while driving. You are driving with the parking brake set. There is insufficient brake fluid in the reservoir. Suggested solution Release the parking brake ( page 48). Risk of accident! Carefully stop the vehicle and notify an authorized Mercedes-Benz Center. Do not add brake fluid! This will not solve the problem. ; 3 Warning! G ! If you find that the brake fluid in the brake fluid reservoir has fallen to the minimum mark or below, have the brake system checked for brake pad thickness and leaks. Driving with the brake warning lamp illuminated can result in an accident. Have your brake system checked immediately if the brake warning lamp stays on. Don't add brake fluid before checking the brake system. Overfilling the brake fluid reservoir can result in spilling brake fluid on hot engine parts and the brake fluid catching fire. You can be seriously burned. 303