New rear brakes dragging??
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Member
Joined: Dec 2019
Posts: 160
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2016 C300 w/ sport package
New rear brakes dragging??
I just had my rear pads rotors rotors replaced at the dealer and am noticing the right rear rotor is getting considerably more hot than the left rear. Even after short 5-10 minute trips the right rear rotor gets hot enough I can only touch it for about 3 seconds before it gets too hot and have to lift my finger, whereas the left rear I can hold my finger on the rotor as long as I want. I'm assuming this means the right rear is dragging or can this variation in heat be normal? When I put the car in neutral I can easily push it, does this mean it's not dragging? I have the sport package if this makes any difference. Kinda frustrated you'd think if I spend the extra money at the dealer you'd get it done right but looks like this might not be the case.
Out Of Control!!
Joined: Nov 2018
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From: San Francisco Bay Area
2019 C63CS
Measuring the rotor temperature is not a good indication of anything. Modern cars all have electronic brakeforce distribution, which regulates the brake force individually to each wheel depending on available grip at each corner, so the left and right rotors could apply different amounts of brake force depending on the available grip. 4Matic cars also use the brakes to control where the driving torque is sent and on cars such as yours that don't have a limited rear slip differential, the brakes are used to distribute torque to the wheel with more available traction. Some cars also do torque vectoring where the brakes are slightly applied to the inner rear wheel around a bend to send more torque to the outside wheel, so if you make more right turns than left turns, the left rear rotor would get hotter. Not sure your particular model does torque vectoring, but if you have 4Matic then it definitely does use the brakes to control the torque distribution between all 4 wheels. But the point is the brakes are used not just when you step on the brake pedal. They are also used for traction control and torque distribution.
Last edited by superswiss; Nov 16, 2024 at 07:54 PM.
Thread Starter
Member
Joined: Dec 2019
Posts: 160
Likes: 14
2016 C300 w/ sport package
I did it after very short trips with very limited and minor braking applications so the rotor shouldn't be very hot, but point taken. I fully understand how hot rotors can get.
