Squealing Sound...parking brake shoe?
 

I have a E550 coupe with 22K miles.I get this squealing sound from the rear brakes when driving away. I had brought it to the dealer twice and each time they say they adjusted the parking brake shoe. A month or two later the problem is back. What should I have these guys do when I bring it back for the third time? I'm feeling like at this stage something needs to be replaced. Thanks,,,

you may have warped rotors or worn out pads or dirty pads.

I have a 2013 E350 and it has the same squealing sound you describe. Mine comes from driver side, rear wheel. I have noticed my car does this noise when I release the parking break AND the car is on a gentle slope. I have brought it to the dealership twice.

The first time they kept the car for three days and they could not reproduce the issue. The second time, the mechanic drove the car with me, I told him what to do to replicate the noise, he heard it and said it was normal. He said the noise happens when the parking break engages, and that it is normal.

I am not sure if I believe his explanation; so I am learning to live with the squealing noise when I release the parking break. ;-(

Note: I purchase my car CPO and MB dealership replaced breaks, rotors and tires as part of CPO. Squealing sound from rear driver side wheel has happened from the day I bought the car; so I am assuming the rotors were not warped, and the pads were not worn when I bought the car.