Hi everyone looking for a bit of help/info i have a 02 ml270 and my local mechanic (mercedes approved) replaced my brake discs callipers and pads (pads now changed twice and got the expensive ones) but there is still a very loud screeching when i brake but only at low speeds. What can be the problem is it the type of discs?? I got the brakes fitted about 5 months ago

 

Is your problem only when pads are cold?

 

Your problem is that your mechanic didnt use lube on your sliders. Gonna have to take them off and regrease them to prevent chatter.

 

Back in the 80's Mercedes decided to do something about the squeal problem they were having so they started experimenting with brake pad composition and rotor hardness.
Eventually they came up with a pretty good formula for both resulting in almost no squeal but increased brake dust.
Now their pads and rotors are well matched with only an occasional complaint of squeal.
They do have a paste that comes in a little foil pack that is used on the back side of the pad to help prevent squeal. P/n A 001 989 94 51 10 if I remember right.
We also used a fluid made by MOC Products to saturate the pad lining to help. Although this is not factory recommended and I'm not sure of the availability.

Here's the thing though. If your repair shop CAN'T diagnose and fix the problem you need to change repair shops.

If they are using non OEM parts then the pad and rotor compositions are mismatched and this will cause a squeal. My recomendation: Take it to the Factory Authorized, Trained and Equiped Dealer when your independant fails you.