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D3 - Axles, Brakes, Suspension and Steering Brakes, Springs, shocks, steering racks, steering columns, suspension arms, wheel hubs etc.

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Old 27th July 2019, 09:20 PM
Durham Durham is offline
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Default S8 Ceramic discs judder

Hi, I am relatively new to using the forum although I have had my D3 S8 with ceramics, for almost 2 years now.
Te car has an intermittent brake judder at approx 80mph. the ceramic discs have been removed, checked and replaced to no effect. Judder worse when brakes warm, Non existent when wet and the judder can be avoided by braking really hard. So I wonder if it could be a suspension problem?
Does anybody have any ideas on the? Or suggestions on who would be best to take the car too?
Any thoughts gratefully received.
Thanks
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Old 28th July 2019, 12:27 PM
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homer simpson homer simpson is offline
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Pads and tyres ok? Btw you have posted in the D4 section
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Old 28th July 2019, 12:36 PM
kele kele is offline
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If the pad has been inserted incorrectly or the backing clip on the pad is bent or damaged, then you can get these symptoms. And the inner pad may wear more quickly that the outer pad but if the discs have been checked then presumably they checked all that..

I had the same symptoms that you describe on my A6 which turned out to be a damaged pad backing clip.
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2019 BMW I3. Heat pump, Winter, professional and comfort packs, Harmon Kardon, autopilot

2022 Mercedes EQC 400

Previously: 2009 S8, Silver, B&O, Ceramic Brakes, Advanced Parking Camera, VCDS
2008 A8 3.0 Tdi sport, B&O
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Old 28th July 2019, 05:19 PM
ainarssems ainarssems is offline
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Worn suspension bushes can produce the same symptoms as well, especially on the lower curved arm.
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Old 28th July 2019, 07:31 PM
Durham Durham is offline
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Thanks guys. Will now post in right section! Don't know how that happened
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2007 D3 S8 5.2 V10
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Old 28th July 2019, 07:43 PM
Durham Durham is offline
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Quote:
Originally Posted by homer simpson View Post
Pads and tyres ok? Btw you have posted in the D4 section
Yes. I think good enough. Judder was there when tyres were new. Pads will need replacing quite soon but evenly worn.. Do you recommend any particular pad for replacement? Also, I understand my discs are ok (9ok miles) but is there a way to check how long they have left?
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2007 D3 S8 5.2 V10
Daytona Grey, Ceramic brakes, B&O, DTV, DAB, 6 CD, TPMS, Keyless entry, Soft close, Auto boot, AMI, Fingerprint, Black extended leather, Heated sports seats, Alcantara, Carbon trim, Power boot, 7 way electric memory seats.
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Old 28th July 2019, 07:47 PM
Durham Durham is offline
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Quote:
Originally Posted by ainarssems View Post
Worn suspension bushes can produce the same symptoms as well, especially on the lower curved arm.
Thanks. Do worn suspension bushes not show up at an MOT test? If not how best to check them?
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2007 D3 S8 5.2 V10
Daytona Grey, Ceramic brakes, B&O, DTV, DAB, 6 CD, TPMS, Keyless entry, Soft close, Auto boot, AMI, Fingerprint, Black extended leather, Heated sports seats, Alcantara, Carbon trim, Power boot, 7 way electric memory seats.
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Old 28th July 2019, 10:16 PM
kele kele is offline
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I read that the discs are good for 180k miles as long as they don't get damaged. Depends on use of course. And I think you have to weigh them to establish if they need to be replaced.
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2012 A6 3.0 TDI Avant, Silver, 7 Spd STronic, Bose, ACC, Advanced Parking Camera, Power close / open tailgate, Side and Lane Assist, AMI & Jukebox, Adaptive lights with corner and high beam assist, Through load with ski bag, Audi pre sense plus, sports diff and sport suspension, Panoramic roof, Storage pack, MMI touchpad and VIM, etc. Oh and now retro fit rear seat entertainment

2019 BMW I3. Heat pump, Winter, professional and comfort packs, Harmon Kardon, autopilot

2022 Mercedes EQC 400

Previously: 2009 S8, Silver, B&O, Ceramic Brakes, Advanced Parking Camera, VCDS
2008 A8 3.0 Tdi sport, B&O
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Old 28th July 2019, 10:28 PM
kele kele is offline
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You can get these discs refurbished by the way

As standard, every new refurbished disc will get new nuts and bolts.

the process is something like this

- Discs are weighed and depending on wear and wear pattern and rotors are x-rayed and examined for structural damage.
- Brake pad residue or contaminates is chemically steamed off
- Discs are machined until they are level
- Napped are vacuum soaked in polymeric carbon
- Pyrolyze the discs at 1100°C
- The last two steps are repeated three times
- Discs are siliconized at 1500°C
- Top layer (ca. 1mm thick) is now restored, and trough the pyrolysis it is chemically and physically bonded with the structure
- Final sanding of top layer
- Disc is reassembled and weighed once more and precision-balanced
- The disc now has gained about 30-50g and is at desired value once more
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2012 A6 3.0 TDI Avant, Silver, 7 Spd STronic, Bose, ACC, Advanced Parking Camera, Power close / open tailgate, Side and Lane Assist, AMI & Jukebox, Adaptive lights with corner and high beam assist, Through load with ski bag, Audi pre sense plus, sports diff and sport suspension, Panoramic roof, Storage pack, MMI touchpad and VIM, etc. Oh and now retro fit rear seat entertainment

2019 BMW I3. Heat pump, Winter, professional and comfort packs, Harmon Kardon, autopilot

2022 Mercedes EQC 400

Previously: 2009 S8, Silver, B&O, Ceramic Brakes, Advanced Parking Camera, VCDS
2008 A8 3.0 Tdi sport, B&O
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Old 29th July 2019, 11:16 AM
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homer simpson homer simpson is offline
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Quote:
Originally Posted by Durham View Post
Yes. I think good enough. Judder was there when tyres were new. Pads will need replacing quite soon but evenly worn.. Do you recommend any particular pad for replacement? Also, I understand my discs are ok (9ok miles) but is there a way to check how long they have left?
I haven't had to replace mine yet but I would get them from Audi. Don't really know of any suitable replacements but haven't looked hard enough yet. As said, the proper way is to weigh them.

Quote:
Originally Posted by kele View Post
You can get these discs refurbished by the way

As standard, every new refurbished disc will get new nuts and bolts.

the process is something like this

- Discs are weighed and depending on wear and wear pattern and rotors are x-rayed and examined for structural damage.
- Brake pad residue or contaminates is chemically steamed off
- Discs are machined until they are level
- Napped are vacuum soaked in polymeric carbon
- Pyrolyze the discs at 1100°C
- The last two steps are repeated three times
- Discs are siliconized at 1500°C
- Top layer (ca. 1mm thick) is now restored, and trough the pyrolysis it is chemically and physically bonded with the structure
- Final sanding of top layer
- Disc is reassembled and weighed once more and precision-balanced
- The disc now has gained about 30-50g and is at desired value once more
Do you know of any UK company that does this?
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