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I bought a brand new 207 '12 and its done its 1000mile checkup.

During this i told them there was a horrible grinding noise comming from when i was breaking, even a metal on metal screech sometimes??

They told me that a stone... got lodged in the brake pad and caused a lip in the brake disc.. so they skimmed the disc.

The problem is the noise is still lightly audible,, like a grinding away when i tap the brake. It brakes fine it is just worrying.

Now in school, when we had geology during geography classes, or physics even.. it is said that only a harder material can scratch or damage another softer material.. ie A diamond will scratch/cut glass and wont ever damage ever.. because it is the hardest natural mineral in the world.

So is it true that a stone.. lets say they hardest available stone on a public road can damage a disc brake causing a LIP like groove in a solid metal disc?

EDIT

OK I went to an independent high street service garage that specialise in tyres,brakes and exhausts. They did a "safety inspection" for me but obviously I pointed out to them a problem with the brakes.

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The front look OK, unfortunately i had not taken pics of the inner sides.. and on both sides they are grooved pretty bad...

They officially wrote on an inspection printout that their inspection reveals that there was no skimming done to the brake disc rotors (in fact one guy told me he used to work for the dealership and they don't even own a skimming machine... besides.. he added, you don't skim discs on new cars any more.. wow...)

The car is like 4 months old.. look at all that rust.. they obviously saving on galvanising bits.. its a joke...

I wish this article get published as much as possible to proove to everybody how dealships pull wool over unknowing customers. I never told them i have years of experience with cars.. and they blatainlty lied to my face.. in my eyes and over the phone. It has jsut become natural to them.. If they told me the truth I would have jsut sold the car after its warranty and never bought a piece of sh** peugot again.

enter image description here

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The worst disc damage I've ever had was when I'd totally burned out the pads on one brake, then what was left just ground the disc until it was paper-thin and snapped off the hub. –  Iszi Feb 16 '12 at 2:42
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2 Answers

Very true. I run my cars in dirt/gravel events and the rotors get pretty scored up from gravel working its way in between the pads and rotors. It makes horrendous screeching noises too. :-)

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I bet your paint job aint great too.. I do not drive off road and my question was geared towards a single stone causing significant damage to justify skimming brand new brake discs.... –  ppumkin Feb 9 '12 at 18:30
    
Actually, the paint job is in very good shape for being 20 years old. There's plenty of gravel to be had on regular roads too. Most of the pits on my windshield all happened on paved roads... –  Brian Knoblauch Feb 9 '12 at 21:02
    
What car is it? :) just curious.. I like doing off road my self.. –  ppumkin Feb 10 '12 at 9:03
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That one is a Toyota MR2. :-) –  Brian Knoblauch Feb 10 '12 at 14:10
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Well, yes, it's possible because it happened.

Remember, your rotors aren't made of diamond. Worse, they're spinning rapidly and the brake pads are pressed into the disk with tremendous force. As a result, if you have the bad luck to get a particularly robust stone, nail or other debris in under the pad, it will machine away the rotor as it spins.

With respect to the remaining noise, you might want to inspect your rotor after it has had a chance to cool. Can you still feel a groove in the metal? Or is it possible that there is still some debris or a rough spot in the pad? If it's just the pad, you should notice the sound fading over time as the pad abrades.

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What if the dealership was lying that they ever took the wheel off and that they just made up a story. When I drove off the same horrid noise was happening.. –  ppumkin Feb 9 '12 at 19:34
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@ppumkin, then turn around and go right back in, saying "you did not fix the problem." Maybe the rock is still stuck in the brake pad. –  Bob Cross Feb 9 '12 at 20:06
    
I am actaully going to go to a brake and wheel place and ask them to inspect it.. because i just don't trust this dealrtship any more. And if I find out they did not skim it and they lied to me.. then what? they obviously have no idea what they doing, right. No point in going back to them. Problem is.. what can i do about it. –  ppumkin Feb 10 '12 at 9:05
    
Oh yea.. If it just caused a lip in the disc.. there is no reason it should be grinding any more unless there is a problem right? I have seen really badly damaged and worn disc (150k miles on the same discs...) and they did not grind or anything(maybe slight feedback on the pedal.. but it was an old car anyway). –  ppumkin Feb 10 '12 at 9:07
    
@ppumkin, it sounds like you have a good plan: go to a shop that focuses primarily on issues like yours. At this point, without pictures of the rotor, it's a little hard to give you constructive advice. Let us know what the shop thinks, though. Good luck. –  Bob Cross Feb 10 '12 at 13:53
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