snowflakeGL

Hi all,

Over the weekend i replaced on all corners pads and rotors with OEM MB parts. Through research here through the forum, there has been discussions with how soft the factory rotors are and indeed they are. I still went with OEM, since i got a very good deal on it. My wife's GLK350 was bought new and has about 42k miles on it. Pads / Rotors have never been replaced until this weekend. I have never seen a rotor wear down as much as it did on a 42k mile suv, that had about 30% pad life left. Anyway, after the pad and rotor change i noticed that the when the brake pedal is depressed it doesn't "bite" like it used to. It requires a bit more pedal force than before. I personally like the new feel, but my wife doesn't.

After i finished the job, i made sure i removed the excess brake fluid from the tank just below the full line, and test drove it around the block by running it from 25-40 mph to a full stop a couple of times.

After my wife complained about the pedal feel, i researched online and found that a proper "bedding in" is suggested to be 45 mph, with a medium-to-easy-slow stop for 3 or 4 times. Then 60 mph to 15 mph 8 to 10 times.

Is this true? Any thoughts on this? Thanks.

AzCamel

What I usually do is 60 mph aggresive dead stop twice, then a 60 mph progressive stop then I park the car and let it cool completely. I would suggest you verify there is no air in the line. Make make sure you brake clean the entire rotor contact surface to remove any oil coating hey had from the factory before install.

snowflakeGL

Thanks, the factory rotors had a white anti rust coating on the rotors which i left alone. There shouldn't have been any air in the lines, but i just bought a motive power brake bleeder and will be purging the lines with new oem fluid this weekend.

Bob338

I think this may have been a mistake. The rotors should have been free of all foreign matter, including the rust protection, when they are installed. All that stuff does is get into the pads and parts of it remain there throughout their life. I think I'd consider removed the pads, washing with acetone and wire brushing them to make sure that stuff is out. Then I'd thoroughly clean the rotors to make sure all of it is off. It HAS to affect the friction between the two while braking and that can't be good. When they turn rotors or drums they are put on with nothing on them but the metal and pad compound.

For break-in I always followed the old recommendation to drive normally and brake gently for about 500 miles before testing for panic stops. Nothing more.