Are these brake discs done

[JohnnieWalker]

Hi all, I've owned my A6 for around 6 months and it had just had a pair of front brake discs fitted when I got it.

I never thought the brakes felt brilliant, but now, although they seem to have plenty of stopping power there's a judder when braking.

It almost feels like ABS, even when braking quite lightly.

Looking at the surface of the discs, they have 'grooves' and also appear to have other marks around the disc.

Obviously this isn't right, and I don't ever remember having this on any previous cars, as the discs should be smooth.

 

[Retroman]

The discs don't look very old - I can't see a lip at the top demonstrating disc wear and the vents look fairly rust free. The surface does look a bit nasty and I can't make out whether that is bad grooves or a disc where the surface became badly rusted (car stood up for a while) and the pads are in the process of scraping off this rust with day-to-day usage. I can't see much evidence of brake dust and so I wonder whether this is the latter and it might be the case that some regular use and deliberate braking - cleans the surface up. Failing that, I've found personally that fitting new pads cleans up rusty discs fairly well.

 

[m_voong]

Did you change pads at same time as changing discs? If not then the worn pads could have scored the new discs as shown. Try changing pads and then once worn in do some hard breaking.

The juddering could be warped disc though so also check that the discs are still true. You can also get the surface ground/machined if there is still significant meat left on the disc.


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[JohnnieWalker]

Only had the car for 6 months and done a couple of thousand miles in it ( due to lock down! )

The discs had just been changed when I got the car, as I had checked the MOT advisory which said they were pitted but not seriously weakened, so had obviously been changed before the car was sold to me, but don't know if new pads were fitted.

There seems to be plenty of meat left on the pads looking at the photo, but not checked properly.

 

[45bvtc]

Only had the car for 6 months and done a couple of thousand miles in it ( due to lock down! )

The discs had just been changed when I got the car, as I had checked the MOT advisory which said they were pitted but not seriously weakened, so had obviously been changed before the car was sold to me, but don't know if new pads were fitted.

There seems to be plenty of meat left on the pads looking at the photo, but not checked properly.

Looks very much like old pads on new discs.

I strongly recommend these: https://www.ferodo.co.uk/products/light-vehicles/eco-friction-brake-pads.html

Check 'buyanycarpart' on eBay, I have Eco-Friction on my cars and no complaints (see https://www.audi-sport.net/xf/threads/ferodo-eco-friction-green-brake-pads-for-the-8p-rs3.397139/)

 

[JohnnieWalker]

thanks for your reply, I've found these, but not sure if they are the ones you recommend ( i have the 1LG PR code ): https://www.buycarparts.co.uk/ferodo/1508009

Standard Ridex brand are about £22, but I imagine the ferodo are worth the extra.

 

[45bvtc]

thanks for your reply, I've found these, but not sure if they are the ones you recommend ( i have the 1LG PR code ): https://www.buycarparts.co.uk/ferodo/1508009

Standard Ridex brand are about £22, but I imagine the ferodo are worth the extra.

Yes! I have 'em on my SQ5, TT and RS3 and cannot fault 'em for road work - and for sure I've tried (ex-automotive design engineer (now retired)) more than a few brands; plus, these are now Mercedes and Audi OEM

PS; and a bottle of 'THE' Black Label if you've any spare for the freely given opinion/advice, lol :

​

PS 2: PLEASE do NOT go Ridex, I do NOT want you following me in any of my machines if and when I practice the as-per-usual late braking....

 

[45bvtc]

thanks for your reply, I've found these, but not sure if they are the ones you recommend ( i have the 1LG PR code ): https://www.buycarparts.co.uk/ferodo/1508009


Standard Ridex brand are about £22, but I imagine the ferodo are worth the extra.

If and when you talk to 'buyanycarparts' they will double-check (before they supply to you) the brake pad size/type/fit with FERODO for your car.

If you go here: https://www.ferodo.co.uk/products/light-vehicles/eco-friction-brake-pads.html you can do a preliminary check yourself - even by your own licence plate!

 

[Gazwould]

Despite Ferodo Eco Friction being a great pad , in this instance the 'brake in' coating to condition the rotors of EBC Redstuff pads looks most appropriate .

Conditions , performance upgrade + low dust .

 

[8YARWY]

Despite Ferodo Eco Friction being a great pad , in this instance the 'brake in' coating to condition the rotors of EBC Redstuff pads looks most appropriate .

Conditions , performance upgrade + low dust .

Redstuff pads what a joke.

Worst pad I ever had on a car.


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[JohnnieWalker]

Thanks for all the info, and yes, I wish I had shares in the Whisky

I know that the discs were definitely new in January this year, as I saw them on the car and it's obvious that there was no surface rust anywhere on them and had just been fitted, and also from what I have read it's unlikely that they are warped due to the high temps needed to do that and I have barely used the car for the last 6 months.

Also, after a recent drive of around 25o miles the discs actually look a lot better, so I'm going to go with the Ferodo pads, and also order some front anti roll bar bushes and also replace the front drop links as they are deffo knackered.

It could be that the hubs weren't cleaned before the discs were fitted, the pads not being bedded in/old pads or possibly some suspension bushes that's causing the issue.

I did a few emergency stops from about 30mph earlier and the car stopped quick enough and didn't wobble or pull to the side, it's just at higher speeds it feels like a pulsing/juddering when applying the brakes.

Discs after a long trip:

 

[Gazwould]

Redstuff pads what a joke.

Worst pad I ever had on a car.


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Personally have 3 cars , 3 full sets .

Redstuff up front on another family car , that's 28 individual pads of satisfaction.

RS3 , S7 etc good reports here on ASN etc .

For sure early versions were shocking and there is a phenomenon about certain people not being able to see past that and not believing improved editions followed .

 

[JohnnieWalker]

I did put my phone through the wheel and take a photo of the pads, and on this image it looks like the pad isn't sitting flat on the disc, like the part of the pad near the centre of the disc is touching but the part of the pad nearer the outside of the disc has a gap. ( photo taken before the braking tests today )

 

[8YARWY]

Personally have 3 cars , 3 full sets .

Redstuff up front on another family car , that's 28 individual pads of satisfaction.

RS3 , S7 etc good reports here on ASN etc .

For sure early versions were shocking and there is a phenomenon about certain people not being able to see past that and not believing improved editions followed .

I know 4 RS3 8P owners who took them off, loss of effective braking and discs polished up like a mirror.

2 RS 3 8V owners reporting the same issues, one whilst at MRC with Doug sat in his car going down the dual carriageway to fine tune his map, car wasn’t going to stop at a roundabout and Doug instructed him to return to MRC where he fitted a set of Ferodo premier pads to his car.

I ran them on an 8P RS3 and they stopped being effective after a few weeks of use.


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[Gazwould]

I personally witnessed Karl taking his B8 3.0 TDI Avant 1800kg worth around Castle Combe for 5 laps until the just upfront Redstuff and std rear pads gave up .

Not bad for a not for track Street pad .


RAF likes them too

 

[Retroman]

In my experience the pad material on brand new pads is around 10-11mm and steel backing plate is an EXTRA 3mm. Your pad material looks roughly around 7mm which, if accurate, suggests they were not new when the discs were replaced - the garage may have taken the view that as they had plenty of "meat" on them, that they would put them back on then car.

 

[45bvtc]

I did put my phone through the wheel and take a photo of the pads, and on this image it looks like the pad isn't sitting flat on the disc, like the part of the pad near the centre of the disc is touching but the part of the pad nearer the outside of the disc has a gap. ( photo taken before the braking tests today )
View attachment 206312

Respectfully you need to check all 4-pads and both inside and outside disc friction surfaces and ensure free movement of brake pistons and caliper - a big job I know but I think the condition of the brake disc the least of your worries; sorry...

 

[JohnnieWalker]

Found an interesting article explaining how brake judder can occur.

The section about "DTV" sounds like a plausible explanation and not something I had heard of, as I basically just thought either a disc was warped or it wasn't, but DTV is probably actually the issue when people think that the discs are warped.

https://www.apecbraking.co.uk/Resources/TechniciansGuides/Understanding-Brake-Judder.aspx?

 

[JohnnieWalker]

And this video shows how important it is to clean your hubs before fitting a brake disc!

 

[45bvtc]

And this video shows how important it is to clean your hubs before fitting a brake disc!

And that's why I had my own SQ5 OEM brake discs Pro-Cut (@ 19k miles) before fitting a set of new Ferodo Eco-Green brake pads and nothing but superb brakes since...

PM sent...

 

[Audidi]

I personally witnessed Karl taking his B8 3.0 TDI Avant 1800kg worth around Castle Combe for 5 laps until the just upfront Redstuff and std rear pads gave up .

Not bad for a not for track Street pad .


RAF likes them too
View attachment 206315

I have them on my Bitdi.
They are far from poor.
Zero dust and the bite is way better than OEM.

some people hate brands.

 

[45bvtc]

I have them on my Bitdi.
They are far from poor.
Zero dust and the bite is way better than OEM.

some people hate brands.

I agree 100% All depends on application/use. As advised by Audi professionals at an Audi Silverstone Experience day in 2015 "you guys don't brake hard enough!"

And I agree; pressing on I found EBC Red Stuff brilliant on our 8P RS3 - low dust and zero low-speed brake squeal - but with constant low speed use I found they lost that initial low-speed bite.

I truly believe brakes and brake pads depend more on 'the driver's and/or driver use/application' than the particular brake/friction material itself.

Maybe this is why the OEM pad offers good 'overall' performance while being poor at offering 'specific' use such as 'track use.'

But as with Audidi, EBC Red Stuff worked fine for me on our 8P RS3, not our TT mind, until our 'use/needs' changed and then we went back to OEM, and gained immediate improvement in the low-speed 'bite.'

However, I now have Ferodo Eco-Friction Green brake pads on ALL of our cars and find them better still - FOR US and our use/needs.

 

[JohnnieWalker]

OK, just fitted new discs and pads at the front and after approx 50 miles it seems that the offside pad/disc isn't bedding in properly.
The old pad I took out had uneven wear, and it seems that the new pads are having the same issue, the inner portion of the disc has a bit of surface rust, so the pad/s can't be touching the disc.

Could it be an issue with the slide pins?

Any help appreciated.

 

[45bvtc]

OK, just fitted new discs and pads at the front and after approx 50 miles it seems that the offside pad/disc isn't bedding in properly.
The old pad I took out had uneven wear, and it seems that the new pads are having the same issue, the inner portion of the disc has a bit of surface rust, so the pad/s can't be touching the disc.

Could it be an issue with the slide pins?

Any help appreciated.

Yes, essential the slide pins are well lubricated (use Ceratec or similar) and the caliper body free to 'slide' otherwise you may well get the uneven wear you report.

 

[JohnnieWalker]

Here's a photo

 

[JohnnieWalker]

Does anyone have a link to some decent pictures, exploded diagram of the calipers, as that would help me visualise what the problem could be.

My calipers are the type in this video:

 

[45bvtc]

Does anyone have a link to some decent pictures, exploded diagram of the calipers, as that would help me visualise what the problem could be.

My calipers are the type in this video:

Start here: https://audi.7zap.com/en/rdw/

And scroll through to something like (or whatever is your car): https://audi.7zap.com/en/rdw/audi+a6+avant/a6/2006-448/

And then chose whatever brake type for your own car:

And then blow that image up, for example and maybe this (guide pins are #15)....

Hope this helps...

 

[JohnnieWalker]

Thank you