Brake Noise

[coolvanilla]

Originally Posted by DZeckhausen

Let me make sure I understand. You're saying the grinding noise occurs while the car is stationary, following a stop? Or is the noise happing just as the car is starting to roll forward again, while you are still applying some very light braking force?

It's after the car has stopped and is at a stand still. As I continue to let off the brake the car obviously inches forward but the noise starts as soon as i start to release my foot from the brake. Also, I don't notice it when it is really cold outside (less than 32 degrees).

[DZeckhausen]

Originally Posted by coolvanilla

It's after the car has stopped and is at a stand still. As I continue to let off the brake the car obviously inches forward but the noise starts as soon as i start to release my foot from the brake. Also, I don't notice it when it is really cold outside (less than 32 degrees).

I hate to say this, but I agree with your dealer. It's normal for the stock brakes to do this on the 300C. What's happening is that you are transitioning from static friction (higher Coefficient of friction) to sliding friction (lower Cf) and it's possible to apply just the right amount of pedal input as you lift off the brakes that you can make your calipers vibrate. It doesn't happen on all cars and it doesn't happen with all brake pads. It requires the perfect combination of conditions to make it start. Think about that crystal glass that you can cause to "sing" by wetting your finger and running it around the rim. If you press slightly too hard or slightly too soft or if you fill the glass, the singing won't happen. Again, it requires just the right conditions to happen.

All you have to do is lift off the brakes a little faster. Bedding in your brakes may also help by raising the sliding Cf and changing the input conditions that are required to make the calipers vibrate. Either way, you have the ability to slightly modify your driving style so that the sound does not occur.

Remember the patient who tells his doctor, "Doctor, it hurts whenever I do this!" And the doctor responds, "Well, stop doing that!"

[coolvanilla]

Thanks Zdeck. I think I was over analyzing. You're right - if I just lift my foot off the brake it barely makes a sound. I just got concerned when no one else said they heard the sound. I'm still planning on trying the bedding process.

[jcsganga34]

Coolvanilla, I have the exact same sound you are describing. I'm glad to hear that everything is normal. I will also try the bedding process when I can. I also noticed that if I lift my foot off the brake faster that it never happens. Maybe all of us in MA learned to drive the same way...speed up on yellow lights, cut off the Yankee fan from NY, slowly lift your foot off the brake pedal

[Rainer]

Also BMW or Mercedes does this sound. Sounds normal to me too.

[bo srq]

Originally Posted by coolvanilla

When I had my oil changed last week I had the dealer check the front brakes. The first 5 or 10 minutes of stopping results in a grinding kinda noise when I RELEASE the brake pedal. No noise when the brake is applied. They greased the callipers but I still have the same noise. Anyone else? Any ideas?

I will tell you from a mechanic friend of mine. Chrysler has come up with an upgraded brake because of the noise on the SRT8. They have a new drilled brake that they wont put on unless you complain about the squeal.

Looking forward to that since they just replaced my pads again. They wouldnt put the mew brakes one until they squeal again. That will be soon from what I hear. Dont be shy, you have to ask for it.

Thank god we can finally break in peace