Shudder

[Mr G]

Hi - has anyone experienced the following and if so - how was the problem solved? Thanx in advance
When braking (normal driving) and when the speed gets to 70km/h there is a shudder that can be felt on the steering.
So I'm doing say 120km/h and start braking - everything is fine, until I slow down to 70km/h - and the shudder is apparent.
Oh this is on an RS2.
New front disc's and pads were replaced about +- 10k kms - OEM parts standard size. Discs and pads still look fine.
Your help is appreciated - what should I be looking for/check?
Cheers

[Greg_S]

Have you done some high speed braking recently to warp the discs?

[john881000]

Hi Mr G
Welcome, to site.......
I am a EX-PAT,by the look on yr number plates are you up in the North Province areas???...I from Cape Town.......

cheers
john

[Mr G]

Hey there Greg
Yes I did some high speed braking -but if the disc is warped, won't the shudder be there all the time and not only at 70km/h ?
John881000 - I'm from Joburg

[Greg_S]

I remember when I had my AP's fitted I had a few issues and guy at AP told me to get the discs warmed up then brake from 30 to 0 a few times and it got rid of the vibration. Fair point on vibration and think you're right about having it all of the time.

Have you had your wheels balanced recently?

[Rusty]

This happened on a mate's B5 S4 with the 2 piece 993TT calipers, they had corroded and were not functioning properly and required a rebuild. Also, as above, it could also be the discs, pads, wheel bearings... Going to be trial and error really, suggest you try some new pads first (cheapest) and then you're looking at discs and a caliper rebuild. Discs and pads didn't sort the problem on the S4 BW. Oh, and check that the wheel bolts are tight too

[GazzaG60]

could be the pads.

what setup is it.

the moat common way to warp um is by having you foot on the brake after you stop from a heavy run. heat on one spot of the disc. next is the pad type and contact size. green stuff originals on stanard discs held too much heat and caused issues. the newer blends of material were for this.

also if you overheat the pad they can warp too.

make sure you bed them in properly and also dont change pad type on the same discs without having them scrubbed up first. first action of a pad is to coat the disc in its material to aid the friction. mixing materials can be a disaster.

[Mr G]

Thanx Guys
Yep sounds like it's gonna be trial and error.
Wheels all balanced and all wheel nuts tight.
Thought migt be a flat spot on tryes, so rotated them also - no joy. tyres are due to be replaced, so might do this sooner then later.
OEM set-up, with Textar pads

[Big Lee M]

The judder could also be knackered wishbone bushes, if there is only a little play in them you would feel it under braking, like mine though i don't get it all the time. I think this is the reason why mine are doing it. But time will tell when i get it back.