Warped brake discs.

So the dual carriage runs were without spacers? Why don’t you get the face of the rotor and the face of the alloys checked/machined to remove any possibly contamination and to ensure they butt up flush? Surely that’s cheaper than more rotors and pads and suspension.
 
Sam. i dont think its rotors or balance simply because its been doing this for ages and 3 sets of discs i think the judder is something loose in the suspension mountings that manifests itself as a judder because the brakes are flexing the suspension slack.
A couple of points, its been doing this for 30k miles, 20k of those it never had spacers. although the discs grab and release when you clock them they are spot on, i even had the J hooks re ground and they still grabbed and released on the MOT brake tester before it even went back on the road. The clock showed them better than .002" run out .
I dont have anywhere undercover to play with it now and its wet and cold in Blighty :)
I cant afford to put it back in the garage, got business tax to find now by end of year.

Its vauxhall vivaro for me now :) its nearly Ibis white :)
 

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Well i bit the bullet and put it back in the garage today. Didn't get anywhere but at least we now now that all the suspension bushes and steering are good. Mechanic took it out and got it to shake on the brakes.
Put it back on the brake MOT tester rollers and although its only about 3 mph you can clearly see the needles moving in unison as the brakes lightly bite...
Run out on the discs is .03mm max allowed is .06mm however its pretty clear the discs have warped as they have one high spot. where as an uneven mounting would be an even high low i think.
I have run out of ideas. I think the only clue so far is Fernando above who mentioned the single piston calipers dont spread the heat evenly like 4 pots
I am also mindful of Lesh and his comment about corrosion on the mountings but the garage guy is pretty clued up and looked almost hurt when i even suggested the mounts were not surgically clean when he fitted the discs :)
I think i need a set of RS calipers which might be a little hard to find...but i suppose with winter nearly here there is now rush. will RS3 calipers fit with std 3 wheels ?
 
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paddy said:
Well i bit the bullet and put it back in the garage today. Didn't get anywhere but at least we now now that all the suspension bushes and steering are good. Mechanic took it out and got it to shake on the brakes.
Put it back on the brake MOT tester rollers and although its only about 3 mph you can clearly see the needles moving in unison as the brakes lightly bite...
Run out on the discs is .03mm max allowed is .06mm however its pretty clear the discs have warped as they have one high spot. where as an uneven mounting would be an even high low i think.
I have run out of ideas. I think the only clue so far is Fernando above who mentioned the single piston calipers dont spread the heat evenly like 4 pots
I am also mindful of Lesh and his comment about corrosion on the mountings but the garage guy is pretty clued up and looked almost hurt when i even suggested the mounts were not surgically clean when he fitted the discs :)
I think i need a set of RS calipers which might be a little hard to find...but i suppose with winter nearly here there is now rush. will RS3 calipers fit with std 3 wheels ?
Click to expand...

I assume you use the brakes quite heavily?

I do too ....

Are they actually warped or do they just have pad deposits on them?

Do you think the high spot is actually the issue or rather something that's developed from another underlying issue??

EDIT: Take a look at tyrol caliper bushing kits.

Also have you read the Alcon brake article?
It's very interesting.

https://alconkits.com/support/brake-pad-info/110-the-real-truth-about-warped-brake-rotors

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Last edited:
I fully agree, i have never come across warped car brake discs but its common on motorcycles, its nearly always friction material transfer so when i say warped i actually mean warped effect. Of course these massive castings dont actually warp :) unless they get mega hot and they are unlikely to do that on the road. I think the point is the friction transfer of materiel is uneven because hot spots occur on the disc and that is down to a small pad area which is lessened with larger brakes and pads. basically the larger the pad area the larger the area of heat dissipation which is why people run 4 pots and 6 pots. Lets face it even my std S3 single piston calipers will fire off the ABS at any speed so the advantage of bigger brakes is more to do with wear and heat dissipation than actual stopping power.

thanks for the article, i will read it through later :)
 
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paddy said:
Well i bit the bullet and put it back in the garage today. Didn't get anywhere but at least we now now that all the suspension bushes and steering are good. Mechanic took it out and got it to shake on the brakes.
Put it back on the brake MOT tester rollers and although its only about 3 mph you can clearly see the needles moving in unison as the brakes lightly bite...
Run out on the discs is .03mm max allowed is .06mm however its pretty clear the discs have warped as they have one high spot. where as an uneven mounting would be an even high low i think.
I have run out of ideas. I think the only clue so far is Fernando above who mentioned the single piston calipers dont spread the heat evenly like 4 pots
I am also mindful of Lesh and his comment about corrosion on the mountings but the garage guy is pretty clued up and looked almost hurt when i even suggested the mounts were not surgically clean when he fitted the discs :)
I think i need a set of RS calipers which might be a little hard to find...but i suppose with winter nearly here there is now rush. will RS3 calipers fit with std 3 wheels ?
Click to expand...
Not without spacers.
Oh and 4 pot rs calipers have better stopping power (even tho standard s3 calipers have huge piston) :kissingheart:
 
Spacers are not the problem, made no difference at all to the effect on the road.
 
Be aware oem ttrs discs are really bad i had them skimmed couple of times.
 
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Thanks Milty but i think i need something 8p , i dont want to go too over complicated on the conversion. Lets face it i am only doing this because it seems like Audi cant make brakes for the S3 that work, good price though.
 
.... Spindles from a Mk7 will even fit the PQ35 platform (brakes etc) .... Stuff is still interchangeable ....
I'd just confirm with the company that they fit ....

NOPE NOPE - Also these "should" fit you current brake lines EDIT: I'm WRONG .... HEL braided an extra 85 quid.
fc9c5f13c8ff9e19202997e74c9c22be.jpg


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Last edited:
paddy said:
Thanks Milty but i think i need something 8p , i dont want to go too over complicated on the conversion. Lets face it i am only doing this because it seems like Audi cant make brakes for the S3 that work, good price though.
Click to expand...
It's not complicated .... It's cheaper and they probably don't have all the problems associated with RS3 calipers ....
Although it's up too you .... You probably can find cheap RS3 calipers .... We can't due to the fact that they only came on the TTrs over here.

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What really bugs me is i cant be sure that spending another £1k on this is going to make any difference at all :)
 
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@paddy - get some new top mounts to discount that. Get some new OEM pads, bin-off the spacers and get some sandpaper and scuff up the back of your alloy face and the rotor seat face before fitting the wheel.

What are your tyres like, get them rebalanced, get the tracking checked?

My J-Hooks were brilliant before my BBK upgrade.

Don’t mess around with the 8V brakes above - you don’t need the complication and expense.
 
Ignore Sam. Spend all your monies
 
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paddy said:
What really bugs me is i cant be sure that spending another £1k on this is going to make any difference at all :)
Click to expand...
Hmm true .... I think you may have a bedding in issue .... I think I ran into the same issue my self.

Did you read the Alcon article?

I'd try getting your rotors skimmed and then put hawk HPS 5.0 pads in, before changing calipers ....

How did you do the initial bedding in?

How old are the calipers on the car? Did you change the bushings to new ones?
Are any of the slider pins bent ....

Also is the pad deposit issues on just one rotor?

Here what I can't understand .......... Many people (GTI guys etc) have run the R/R32/S3 brakes as an upgrade .... With much success .... So I think the issue isn't the brake type but rather something that's been over looked or there is something just a bit loose on one of the sides.

Also you have eibach front springs right?
So your top mounts shouldn't be too old??

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Hi Sam
Tracking done , wheels balanced to 1g and swapped front back, spacers removed, OEM std s3 discs and pads fitted, tyres new Goodyear iso 2 F1

Had it in the garage yesterday and checked all the suspension including top mounts.
 
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Top mounts were done with the Eibachs, also wheel bearings changed and drop links.
when the new discs were fitted it solves the problem for about 3k miles each time for 4 sets, 2x std audi, 1x EBC ,and 1x j hooks.

when clocked hot they defo run further out of true than when cold but that could just be uneven heat because of friction material transfer.
 
paddy said:
Top mounts were done with the Eibachs, also wheel bearings changed and drop links.
when the new discs were fitted it solves the problem for about 3k miles each time for 4 sets, 2x std audi, 1x EBC ,and 1x j hooks.

when clocked hot they defo run further out of true than when cold but that could just be uneven heat because of friction material transfer.
Click to expand...
When did the juddering problem start? And how long before that was it, that you had anyone work on your car?

Just trying be a detective, ha!

It's certainly not your pads or rotors .... So look towards you calipers for motion issue.
Dragging, sticking, bent parts, etc!

Is the problem affecting both rotors?


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Ha ha problem started 3 years ago or 30k miles, it developed a bad judder on the brakes at 40k miles, i booked it in to the garage for new discs and the guy fitted them but said the old ones were spot on.... that was the start. Owned the car from new, never had a bump or anything.
strange thing is it has a high speed wobble like a balance issue but at 75mph but you drive through it by 90mph, this must be linked to the braking issue. The braking judder is a lot worse at 100mph + but is hardly noticeable usually below 70 mph.

Calipers is a possibility as they havnt been touched to the best of my knowledge although they were cleaned up each time new pads have been fitted. but why would calipers cause a speed wobble when off the brakes ?
 
paddy said:
Ha ha problem started 3 years ago or 30k miles, it developed a bad judder on the brakes at 40k miles, i booked it in to the garage for new discs and the guy fitted them but said the old ones were spot on.... that was the start. Owned the car from new, never had a bump or anything.
strange thing is it has a high speed wobble like a balance issue but at 75mph but you drive through it by 90mph, this must be linked to the braking issue. The braking judder is a lot worse at 100mph + but is hardly noticeable usually below 70 mph.

Calipers is a possibility as they havnt been touched to the best of my knowledge although they were cleaned up each time new pads have been fitted. but why would calipers cause a speed wobble when off the brakes ?
Click to expand...
Now that your mentioning a speed wobble .... I think your brakes might be fine .... Unless the wobble only happens after the brakes start going bad.

There's a vendor on the classified section selling a set of S3 front brakes .... Not sure if there V or P.

It's got to be something else other than brakes .... Have you ever seen the hubs/bearings yourself? .... And did the problem start before the new hubs/bearings were installed?

Maybe go to a different tire shop with a road force balancer to see if your wheels are balance .... Some shops don't necessarily always calibrate there's .... Not saying that is the case always.

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To be honest its even been to 3 tyre places. My usual set the machine on over ride to go down to 1g, usual default is 5g. All places confirmed each other.
Tyre balance manifests itself at much lower speeds , usually 40mph or around.
when the problem started the car was 4 years old its now 7. i have changed virtually everything, cost is above £3k so far. its exactly the same now as it was 3 years ago, it started doing this one day and its not got worse, its just the same after another 30k miles
 
@paddy have you ever had the calipers rebuilt? Pistons could be sticking or the pad sliders could be at fault.
 
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I think calipers is the next step if only because i am running out of ideas :)
If it wasnt for the tax man chasing me i would just go for a set of Vagbrem discs and AM calipers @ £1k as they seem to be a straight fit and i want to upgrade with the least hassle now as i dont want to add to my problems with spacers and over size wheels etc.
 
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paddy said:
To be honest its even been to 3 tyre places. My usual set the machine on over ride to go down to 1g, usual default is 5g. All places confirmed each other.
Tyre balance manifests itself at much lower speeds , usually 40mph or around.
when the problem started the car was 4 years old its now 7. i have changed virtually everything, cost is above £3k so far. its exactly the same now as it was 3 years ago, it started doing this one day and its not got worse, its just the same after another 30k miles
Click to expand...
So do a list of what you haven't changed ....

That'll actually help I think.

https://r.tapatalk.com/shareLink?ur...&share_tid=382011&share_fid=2376&share_type=t

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Hello,
My experience so far is to check new disc run out with a dial guage, after cleaning rust off old hub surface to get no more than a tenth of a mm per rotation of the disc for our cars , if you have more you will get the Thickness variation leading to judder etc , have just replaced all 4 discs and hubs to get within specified tolerance , if you don't replace hubs you will get judder every time after 3 to 4000 miles regardless.
 
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Hi
This is interesting. What is the thinking behind changing the hubs as well ? As soon as we get some dry weather i will clock the discs on the car. and clock the disc face on the hubs.
I was a toolmaker for 35 years and getting things running true is second nature to me, lathes i could get to run to .001" depending on the chuck but when grinding i could get down to 2.5 microns or about 1/10th of a thousandth of an inch :) 10th of a mm shouldn't be to bad :)
 
paddy said:
I think calipers is the next step if only because i am running out of ideas :)
If it wasnt for the tax man chasing me i would just go for a set of Vagbrem discs and AM calipers @ £1k as they seem to be a straight fit and i want to upgrade with the least hassle now as i dont want to add to my problems with spacers and over size wheels etc.
Click to expand...

You’ve just dumped your Vagbrem rotors, why would you go for these again?

Get your existing calipers rebuilt and some new pads, I think you’ll be fine.
 
Simply because it looks like the rotors were not the problem. I have so many boxes or nearly new pads :) please not another set :)

I will order a couple of caliper service kits tomorrow.
 
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Rebuild kit is £3.09 inc vat, its just the rubbers and i can see they are fine.
 
Due to the calipers being cast iron of some sort (read: rough and not the most refined machining if at all) .... I'd suggest just getting new ones .... & Tyrol bushings.

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paddy said:
Rebuild kit is £3.09 inc vat, its just the rubbers and i can see they are fine.
Click to expand...
Or rather you can rebuild the calipers by pulling them apart as much as you can and replacing the rubber, the bushings and then re-grease them all .... Also install new slider pins.

Will be fairly cheap.

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I’m no expert on this by any means but I think you do have to look at the calipers now. I’ve just re read through this thread and that’s the only thing left by the looks of it that you haven’t touched.
I suppose it’s a process of elimination and now your left with the most expensive thing that could be at fault as you've already changed or tried everything else.
I read that a guy further up the thread had the same issues as you and his problem was sorted by changing to rs3 calipers.
If the problem is the caliper(s) then when you are changing to new discs and pads then i suppose it’s going to take a bit of time before the dodgy caliper(s) messes the new ones up again.
Id previously been thinking maybe a bush or mount might have gone somewhere or like someone else suggested with the top mounts on the suspension but if that were the case then surely you would have the problem constantly but looking back on your posts you say the problem goes away for a little while when you’ve previously changed discs and pads and then it resurfaces again.
I think you’re doing the right thing in now rebuilding and cleaning up the calipers as I suppose replacing them is kinda last resort if you have to.
 
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Been reading this thread with interest.
My A3 2.0 TDi Quattro 2010 has similar brake judder that you are describing, like you I’ve tried most things, pads, discs etc & have come to the conclusion that it is the calipers at fault.
I put new sliders on, greased up & it was fine for a while. Then the judder returned. If I lever the calipers with a screwdriver it’s ok again for a bit.
I think the casting on the calipers has worn allowing the sliders to twist a little under braking. New calipers are next on the list.....
 
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Chris Parrott said:
Been reading this thread with interest.
My A3 2.0 TDi Quattro 2010 has similar brake judder that you are describing, like you I’ve tried most things, pads, discs etc & have come to the conclusion that it is the calipers at fault.
I put new sliders on, greased up & it was fine for a while. Then the judder returned. If I lever the calipers with a screwdriver it’s ok again for a bit.
I think the casting on the calipers has worn allowing the sliders to twist a little under braking. New calipers are next on the list.....
Click to expand...
http://www.tyrolsport.com/braking/tyrolsport-brake-caliper-stiffening-kit-for-vw/audi/

I think this should really help .... I run it .... Brakes feel robotic.

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Hi again, yep done the lot myself caliper rebuild shocks bushings , the disc run out for these is a tenth of a mil maximum , I too have changed the discs since owning the car 4 times twice as they were down too minimum thickness and twice more because I thought 6 tenths runout with the original hubs / bearings was ok (it isn't) 1 tenth max , couldn't believe the hubs were serviceable , or would pass mot but be too slack and distorted so as too throw the discs too far out of alignmant, but since replacing them dialed in just umder a tenth and no more judder. Got the hubs from autodoc and 123 spare parts all good OE standard , got the FAG make they come with all 5 bolts and look identical to Audi the original 1 which Ireplaced a few years ago, if by chance you need caliper parts for another day you may have time to be bored check out Big red online they have the lot think they are in worcestershire. Also about a year ago I had all 4 disks lathed on the car because of the judder this fixed it completely ,but and there is a but a
month or so later I removed the discs to fit new back plates and yes the judder returned , this convinced me the hubs had to be swapped think I'm going nuts . Oh yes something else I did mark the discs so they went back in the same place .Keep smiling hope this helps someone.
 
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Right then
Tonight i have ordered another set of S3 calipers. 30k miles, on ebay, made an offer of £200 and got them.
I have also ordered from AKS the tyrol pin and bush kit for them and i will order a seal kit tomorrow as well.
This way i can refurb these replacement calipers without taking he car off the road and sell the old ones later.
As it happens i refurb motorcycle calipers for a living so how hard can it be :). I will strip them, get them ceramic coated and rebuild with all new parts.
watch this space, eventually i will fix this and save a lot of people hassle in the future :)

Most importantly though, thanks to everyone for their help and thoughts/ideas.
 
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