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 C300 Replace Brake Rotors When Pads are Worn and Squeaking
Mercedes-Benz C300 Problem
Visitor, 2012 Mercedes-Benz C300, 27,600 mi
Its been about 2 years since I leased my 2012 C300 and recently been experiencing a squeaky noise coming from the right side of the car. I brought it in to the dealership and they said it is a brake pad issue. Weird thing is, when I got the car serviced a few months ago, I reported the issue and at that time they didnt make a big deal out of it until now when the problem has gotten worse.
The issue occurs when i drive a long distance and then as I roll at about 15-20mph it squeaks terribly. It gets even worse when I brake. Not sure if this issue is common. :-/