Henry964

My car has developed a grinding sound when braking but only after doing at least 8-10 kms or more.It sounds like the sound the wiper blades do when the windshield is dry.
I took it to my mechanic,they changed the front pads (they were due to change soon) but the sound is still present and still only after making a few kms

911Jetta

I also occasionally feel/hear a similar grinding sensation during braking, but only during from low speeds and with a light tough on the pedal. Accumulated grit on the pads? I think it's telling me to do a couple high speed blasts and stomp on the middle pedal!

joey bagadonuts

Is this noise coming from the front brakes? Do you feel vibration through the steering wheel? Which pads are you using? Do you use race pads for the track?

Since you changed front pads and the noise continues, my guess is that there may be some excess pad material on the front rotor(s). Did you break in the new pads, i.e. accelerate to 90-100 kmh, several times, and then brake firmly? If the noise continues after this process, then you may need to clean the rotors.

breale01

I have developed a grinding noise as well, but only the left rear. Started after my first DE with new track pads (Pagid RS42 light blues). They had been broken-in when new (or so I thought). I'll be trying some more high speed stops soon.

The sound is more like metal-to-metal, or a small rock caught between rotating parts, rather than wiper blades on a dry windshield however.

Henry964

Thanks to all for the help!!!

Now answering Joe questions:

The noise is clearly from the front
No vibrations at all
New pads are Textars OE, old pads maybe the same, I use pagid blues at the rear but couldn´t get them here this time
I don´t use racing pads
I didn´t break in the new pads but the noise was there with the old pads as well and they were used in many DE events so probably they were well breaked in

joey bagadonuts

This is difficult to diagnos without hearing the brakes. Can you describe the sound in more detail?

For example, does it sound like a squeal ... similar to the loud, high-pitch squeal made by a bus when it brakes? A squeal is how I would describe the wiper sound on a dry window--not grinding.

Or is it a true grindng sound, like a coffee grinder or dragging a piece of metal across asphault?

If it's a squeal, you can Search for many answers on how to fix this but, generally, you need to clean off the rotors. Hawk Blue racing pads will accomplish this and you can use them for the street, however, they take just a little more effort to warm up than street pads and you should clean up any brake dust immediately. The compound can be difficult to remove if left too long on the wheels.

misterbeverlyhills

I had the same: when cold hose the brakes with water and get as much dust off, you should see a ton of it come off, the water fairly black with it.
Then take it to 100 mph and stomp on the brakes to a standstill. Repat 1 more time. Mine have been fine since.

Henry964

Thanks!!!! I will try your suggestion

carreragttech

Does the sound change when you change the load from left to right by turning the wheel. I t may be a wheel barring going.

ian89C4

+ 1 on the wheel bearing idea.

I had stock pads on the car for my last DE and I was going a bit faster than I normally did . I cooked the brakes pretty well and I had a lot of excess material on the rotors. There was a definite feel in the pedal, you will know when this happens, trust me. I ended up having to have the rotors turned to get rid of it all.