Brake warping
 

Morning chaps.

I've been getting intermittent brake warping on the front brakes on my D2 S8. I have the discs skimmed then a couple of months later they are warped again so it's back to the skimmers. This has been happening for some time now and I cannot for the life of me find what is causing the problem. However, a couple of years ago I replaced one of the front wheel bearings. As most of you will know these bearings are fitted into a mount and the hub is pressed into the bearing then this unit complete is then fitted into the hub carrier. I had this done by Audi as I didn't have access to a press but this warping problem occurred after I had this done. Could it be that the bearing unit was not mounted onto the hub carrier correctly and is very slightly out of line? If it is then this would put the brake disc out of line in relation to the caliper. I use EBC discs with yellowstuff pads and have never had a problem with them before. Has anyone else had this problem?

Thanks

Steve

Yep, i have cooked a few sets now. I put it down to poor driving, i used to be really bad for leaving it in D and running up to roundabouts and junctions and keeping my foot on the brake this localises the heat and boom warped disc. I have a regular journey that has duel carrigeway that has roundabouts on it.

I now flick it over in tip and used engine braking by coming down the box and then if i have to wait then handbrake up and foot off the pedal.

I have this problem at the moment with my new S8, I get brake judder braking from anything over 20mph so I'm guessing the discs are warped. I will have to investigate the cause though, because if its not just the discs/pads, if its a sticky piston for example, then putting new discs/pads on will just warp them again.

Also found that trying not to use the brakes for 3 years doesn't work either, you have to use them and after a while it in turn knocks the caliper pins / bushes and they end up all rattley. That or excessive movement on the rattley caliper gives the same effect as a warpped disc.

You may well have the classic corrosion problem under the stainless plates at either end of the caliper that the pads track along. The corrosion lifts the plates proud of the caliper body, and can stop the pad fully retracting when you release the brake, causing the pads to drag on the discs and over heating them. I trashed a front offside disc in less than 20miles because of this. Ultimately had to have the calipers refurbished.

Zip

The S8 and my previous RS2 is the only Audi's i've experienced warped discs on. S4/S6 has never had this problem no matter how the car is driven. So i have come to the conclution that Brembo Monoblocks really suck unless new or refurbished every 2-3 years

I wish there was a "Bolt on" brake kit from another Audi that would fit not using Brembo's.. Could be smaller brakes since the S8 really dont need 345mm to stop on road or track.

But for the moment i'm ordering the new seal/dust cap kit to do the refurbish my self.

Just my $0.02

:)

Coupe of things caught my eye.

1) EBC Discs. I had them on my D2 S8 with Redstuff pads. Ran them in properly and they still warped. Though I later found out that the pads were jammed tight in the caliper and not free to move properly. The common consensus is that EBC pads need modification to fit, ie, file down the sides to allow them to slide freely.

2) Even with 345mm discs and Redstuff, my brakes were smoking wrecks after one lap of the Nordschleife. On the road they are enough, on the track not even close.

Certainly Nordschleife will bring hell to your brakes. But the way you use your brakes on the track is just as important as the size of brakes. (within reason)

I have spent several hours and hundreds of laps on different tracks here in Norway, mostly with my S6 2.2TQ wich has 314mm discs and has equal weight to the D2 S8. Never experienced brake fade, even with better lap times then lighter more powerfull audis.

Even when we had a full day with R8 V10 on Spa Francorchamps in Belgium somebody managed to "run out of brakes" with poor laptimes in the R8...

Not at all saying you do not know how to use you brakes on the track just pointing out that very often on trackdays people complain about their brakes and when you join them for ride its easy to see why... Braking to early already heating up the brakes before adding the last pressure to reduce speed enougj to take the corner.

Also i advice DOT 5.1 racce brake fluid as it makes an enormous improvement against fade.

:)

I'm in an A and have warpped 315mm and the slighlty bigger one from the PF S both Lucas / Girling, so this isn't just the Brembo's.

The refurbish i need id not just the rubbers and a clean, they rattle is the pins / bushes that have worn and i think from the warpping of disc's. That's all i can put it down too.

You could change your later hub to the steel type and then brakes to PF. Most people do it the other way so should be loads of parts available.

Tell you what i'll do you a favour, you send me your Brembo's and i'll swap them for a worn set of Lucas foc, you pay postage.

I didn't realize it was such a common problem. It is pretty clear from your replies that the calipers could do with some attention. I'll have a close look at them this weekend and see what condition they are in. Where is the best place to get refurb kits? Remember, I'm in Dubai.

I'm not 100% convinced it's the disc/pads as I was using the same combination for some time without trouble before the warping started.

I had slight brake judder a while back and after changing out the pads it got worse so the discs were changed with no real difference. Changing the front control arms (MOT advisory) at around the same time did help tremendously but did not cure it totally. Then both the new pads (pagid) and new discs (Audi OEM) were replaced under the parts warranty and it was found that the new pagid pads were cracked. In the end it was difficult to say what was the initial cause but it had me and the mechanic stumped for a few weeks.

Sorry to drag up an old thread, but this is exactly what seems to be happening to mine. Discs warped, a new set of Brembo discs with Pagid pads fitted and bad warping again after taking it easy for a couple of hundred miles.

Should I look into the callipers and pins? I often hear a clicks or clattering of what I suspect are the pins when manoeuvring and braking while parking

I'm also having problems with my front brakes. If you fix it yourself or find a garage in Essex worth recommending please let me know. My garage is stumped at present. I had front discs and pads changed and when I got the car back I felt the brake pedal was very spongy and brakes didn't bind till my foot was on the floor. Initially I thought they hadn't fitted the discs and pads correctly or bleed the brakes properly. I was embarrassed to accuse a mechanic of not being able to do a simple job so I gave them licence to fix the problem hoping they would admit to a simple error on their part. So I Brought it back to garage and they've been looking at everything else except how the discs and pads were fitted.

They started by saying the brake pipes were corroded and disintegrating in places. So they set about replacing some of the ones they could access but didn't touch the one were they would have to drop the gearbox. No joy, now the problem is permanent binding on of the brakes. They think it could be a master cylinder problem.

What next!!!!!

From reading this thread, Maybe it's the corrosion of the calipers maybe it's the way some pads don't fit correctly and wear excessively and cause disc warping. I also heard strange noises when parking and steering at slow speed. :mad:

I just want my car back :Confused:

I would get the callipers checked, sounds like you might have a sticky/stuck piston

I can wobble my caliper through the wheel and replicate the rattle i get.

So many things it could be. Sticking piston, pads rattling around, control arms, warped discs again (unlikely), calliper knackered, hub misaligned...

Think I should start with the calliper.

On a number of occasions, just after having new pads fitted, my pads have rattled, especially the rears. In every case, I believe it was the clip that holds the pads in place had been incorrectly fitted. Each time I just took it back to the garage and, after a bit fiddling and fettling, they managed to refit the clip correctly.

Sorry for dredging up the old thread here, but I'm just going through the brake forum trying to find some info on a different problem

But for peoples information, you dont actually warp rotors. It's an issue of uneven material transfer onto your rotors
http://www.stoptech.com/technical-su...nd-other-myths