Due to the size and material used on the brakes of these vehicles, the brakes may start to squeak around the 50 percent wear point. The brake rotor surfaces become uneven, causing a lip to form at the outer edge of the rotor. Because of this, the rotors are usually replaced when the pads are worn (pad life varies depending on driving style and terrain).Google+
Car Problem Reports
Mercedes-Benz E550 4MATIC Replace Brake Rotors When Pads are Worn and Squeaking
Mercedes-Benz E550 4MATIC Problem
Average Mileage: 28,500 mi (16,000 mi - 46,000 mi)
All of a sudden when applying the brake there was vibration in the brake pedal and steering wheel. So, we took it to the dealer. Brake pads are fine but the front rotors are being replaced! I have only 29000 miles on the car. I will be writing to MBUSA to complain.
Visitor, 2010 Mercedes-Benz E550 4MATIC, 16,000 mi
Rotors and pads replaced as a CPO purchase. Same problem 16K miles later. All highway driving, no riding the brakes.
Visitor, 2010 Mercedes-Benz E550 4MATIC, 23,000 mi
Rotors replaced under waranty @ 10k miles.
Occured again @ 23K. Mercedes will not replace again since they already did it once