Brake Fluid Leak problems of the 2004 Mercedes Benz ML350

While driving on a local street, I noticed that brakes had stopped working. After investigation, I noticed that a corroded brake line was leaking brake fluid. I had contacted Mercedes Benz customer service. I was told to contact a dealer, who confirmed that all brake lines are corroding in the area close to the engine compartment. I was told that this is not a safety issue subject to a recall. I was further told that it is normal for brake lines to corrode and leak. I have not noticed corrosion on any other part of the car, except the brake lines.