New discs - Wobble under braking.

[willu17]

Hi All,

After a little bit of advice. I’ve just changed my front discs and pads (Brembo discs/ebc red stuff pads). The discs have covered about 300 miles so arn’t really out of the break in stage yet. I’ve not driven hard so no way they are warped!

However, under braking I’m getting some wobble. Nothing severe, but given I’m looking to sell the car, enough that I need to address it.

Question is, where should I look first?

- do you think there could be something on the face of the hub that is kicking the disc off slightly? I did clean the hubs with a fine wire wool before applying copper grease, and then the discs so assume they are bedded nice and flat.

- otherwise I wonder if it’s a wheel balancing issue that feels worse under breaking because of the load of the wheels. I’m not sure if I’m imagining it because I’m looking for something, but I don’t know if I can’t feel a very minor vibration under calm driving.

- something else to consider? Rear discs are by no means new, but still plenty of meat on them and I doubt the rears would be working hard enough to create any wobble?!

Any advice greatly appreciated.

Best,

Will

[Royclarke]

I’m 90% sure it will be bad pad transfer,start using the brakes harder to get the pads to transfer evenly,I’ve got a c7 rs6 which people say are renowned for warping the disks,I didn’t believe it until they started juddering,turns out I was getting over spray off the wheel cleaner on the disks,because when it hit winter I got someone else to clean the car and it went away and then I clicked

[RichT128]

Have you had the alloys refurbished recently? My car turned into a case study for the audi chief techs (multiple sets of discs and pads getting brake judder), the best guess in the end was that it was linked to the alloy refurbishment. (They fixed it by fitting ceramics - not what you want for selling it though)

Sent from my SM-G973F using Tapatalk

[willu17]

Hi Both,

Thanks for your input.

I’m hoping that it is as you say @royclarke that it’s a case of just bedding in the pads. I had an issue before I swapped the discs which is why I replaced them, so was worried it was a more long standing issue. That said the previous discs were in a Sorry old state (they hadn’t covered many miles in the last 3-4 years) and as a result were heavily pitted and corroded and the wobble under braking was very bad when compared to how it is now. I think I’ll finish the bedding In process as you suggest before looking elsewhere.

No recent history of a wheel refurb FYI..

[m5killer]

Possible buckled wheel, I had similar and that's what the problem was a buckle in front wheel after hitting a pot hole

[The_Coat]

Not sure where you are in the county but this guy is well worth a phonecall.

Marcus is well clued up on brake judder.

http://discskimmers.com/disc-skimming/

Sent from my Pixel 4 XL using Tapatalk

[Covkiller]

Your discs are not warped, EBC are sh!t pads but I dont thin this is ain't your problem.
Did your get a wobble before you changed the disks and pads?
You say you applied copped grease to your hubs after cleaning, clean this off and give it a try.
Bedding in disks is bolx, just drive the car normally they will bed themselves in.

[johnnydog]

If by wobble, you mean 'brake judder' read on, but if you mean what I would describe as 'wobble' (people describe symptoms differently), then maybe other suspension / steering components need removing from the equation first.
Do a search on 'brake judder'; there are plenty of topics re this on the B7 forum. I went through extensive problems with so called 'brake judder' in 2010 when my B7 was still under warranty which was well documented on here - two sets of new discs / pads, rear discs / pads, new hubs, and calipers etc, but eventually Audi agreed to fit the ceramic upgrade (only fronts available) and it cured the problem immediately. 'Stu' from Newcastle way had exactly the same problems and got the same ceramic upgrade from Audi under warranty, which also cured his problems.
Apparently, there is no such thing as 'warped discs' - the issue is basically a build up of pad material on the disc face due to heat build up. If you find these related topics, there are links to brake manufacturers testing etc, and all is clearly explained with thoroughly detailed reports on the issues and causes, with preventative measures.
Incidentally, I changed to a B8 in 2015, but when looking to change, decided to go for ceramic brakes due to the issues with my B7 brakes, and they have been superb to this day.