brankulo

hi guys, any idea what causes damage to the discs even when pads are only half way worn?
i noticed all my discs have now very delicate circular ridges and the discs seem to have just a slight humps when i drag my finger from center of the disc out?
i started noticing some minor vibration on braking when going down mountain passes. on general braking driving in town there is no vibration but i guess more sustained braking or harder braking going downhills triggers the vibration.
i generally dont do any hard braking if i am not forced to do so. i assume i will need to replace discs and b pads soon?
thanks

A4Audi4Fun

Possibly a small pebble embedded in the pads or random build up of pad material on the rotors. When going on a long downhill IMO, firm application of the brakes for a short period of time is much better than slight pressure for an extended period of time .

Do a search for brake pad bedding in procedures and try that to see if you can more evenly deposit the brake pad material across the rotors.

Greg2022q5

You don’t mention the year or mileage of your vehicle so it’s hard to discern what wear might be occurring.

My own experience with our 2022 Q5 with under 30,000 kms is that the original front brake pads used to freeze to the discs after I washed the vehicle and garaged it with the parking brake on. After, at highway speeds under moderate braking there would be a grinding noise that did not occur at lower speeds. Thanks to members of this board my problem was identified as pad witness marks on the discs (see photo below).

I had the front discs and pads changed out on my own dime as I live 2 1/2 hours away from the nearest Audi dealership. When I initially contacted them about this problem the first words were “brakes are not covered by warranty.” My response was “even if there’s a manufacturers defect?” There was no response to this. I did not want to enter into a protracted fight with Audi and/or multiple trips to the dealership so I bit the bullet.

The positive change in braking was immediate and lasting.


Pad witness marking

brankulo

mine is 2018, 69k miles.
i am not getting grinding noises, no noises really, just slight vibration and what feels sort of like drag, under hard braking.
picture of my discs below

Wires

You need new discs and pads. It looks like rocks/sand got between the pads/rotors and wore them unevenly.

Are you sure the pads are only 1/2 worn? What does the inside pads look like? They both don't wear evenly.

Greg2022q5

Does anyone turn brake rotors anymore? Or just replace?