Brake "Judder/Vibration/Noise" above 70

B8 S4
#1

I did a couple searches and got a few different answers so figured I would start my own post to lock it down before I make a purchase.

Highway speeds or higher only
Medium to hard braking (after a spirited peddle to the meddle run)
Nothing at low speeds or “normal” braking
Stocks Pads, stock rotors
1 track day in cars life
Driven hard usually if not aggressive on the way to work when I can
30k miles
Pads per Audi oil change at 25k (I do them every 5k miles and pay) were “yellow” and will need changing soon, but visually had half the material left
Rotors, front side, visually look normal

So, is it just a used and abused brake situation and just need to replace the pads/rotors/pads&rotors?
Some people were saying it could be a suspension end link or rod, I have the adjustable (SPC) up front and they look fine, no rips or tears on the boots.

Anyways looking for things you guys can tell me to check, or if these all check the box for replacement of Pads/Rotors

Thanks gents!

-AZ

#2

Re-bed your pads and after they cool, try again. Sometimes can be pad deposit on the rotors.

A frozen caliper or float pin can do the same thing, that’s next to check, assuming you have sufficient brake pad material. Check the inside pads too.

If you want a replacement recommendation I have been good with the HPS pads and ATE super blue…not sure what color it will be now that it’s ‘illegal’ lol. I use brembos and FM1000s in the summer though.

#3

I want to go BBK but none of them fit with my summer wheels :frowning:

19’ Forgestar CF10

Anyways does it sound like the rotors and or pads is the issue then?

If so should I go with JHM / ECS / Adams two piece light weight rotors?

will look into the HPS pads, ceramic I take it? Any different levels (track/street) on those?

#4

That’s crazy…BBK can’t fit those wheels? I almost fit the 380 brembos on 18" forgestar cf-5s, but was a couple mm too tight. They fit fine under the 19" peelers.

Re-bed your pads, just do 7-8 consecutive braking events, like 60-10 mph, giving 20-30 seconds in between events, and not stopping fully ever. Then run for as long as possible without touching the brakes at all, give it a few miles at least to make sure your brakes are cool.

If you still have a problem then pull your wheels and check the above things. I’ve only used the stock and the hawks on the stock caliper and rotor, so I don’t have much to contribute there, I’d seen Salmon run his pedal to the floor at the track on a stock setup and he must have done 30-40 laps but his pads were ok - not sure what kind of pads though. Then he kept driving more laps lol…he was fast even without brakes

#5

I was successful in eliminating my brake shudder and vibration by “scrubbing” my discs with race compound pads. For reference they are a stoptech bbk. But, it worked. The street pads were not abrasive enough no matter how I tried to rebed them. Since reinstalled street pads and so far so good. So I agree with j but I don’t know if rebedding street pads will successfully remove pad deposits. Mine would not, but track pads did remove it. Afterwards the rotors were noticeably more consistent with a clean even sheen.

#6

Interesting

#7

Stoptech recommended procedure actually. Use more abrasive race compound pads to remove deposits. I drove around just normal daily use for a couple weeks, then did a modified bedding process with multiple stops from like 60-30 as I didn’t really want to fully bed the race pads per say, just “scrub” the deposits.

#8

wow, seems the stock pads suck at all tasks it seems…I haven’t tried re-bedding stock pads so that’s good info. Worth a shot though.

Anyhow I think most new pads usually have a wear compound on the outer face for removing deposits.

#9

The pads are really easy to swap out on the st40’s so figured why not give it a shot. Glad I did. I think the street pads got overcooked by previous owner using them for a few track days. Not good.

#10

You need new brakes anyway, why mess with it? Just replace your brakes. You could try re-bedding but I bet you have a line of pad deposits burnt onto the disc from a hard stop. Nothing will remove that. There is an article on the stop tech website about it.

#11

Funny I had the same sort of issue, I have a set of forgestars I run as summers that we threw on my other car to test fit wider rubber and they wouldn’t fit over by porsche BBK even though the offset etc was right for it to work.

#12

I just got some 19x8.5 Forgestar CF5Vs to run as summers and was also surprised that the maximum offset I could do to fit over even the stock brakes was 35. I was thinking of doing ET38 or 40 before. Stock peelers are ET43 in the same size I think.

I think this is due to the inherent concavity of the spoke design. Looks great but less practical for BBK. They weigh in at only 21.5 lbs each though which I’m pretty happy about. I guess it’s on par with other rotary forged/flow formed/whatever other names the marketing departments come up with.