brake judder

[Gogs-S3]

seem to have a problem wiith the brakes on my S3. the brakes seem to be juddering badly when braking. The problem has occured before so i changed the discs for drilled zimmerman discs with standard audi pads which solved the problem for a while but the problem has come back. I'm guessing the new dics are warped as they were before. Anyone any idea what can be causing this to happen, i don't thiink i'm particularly heavy on the brakes. What is the main cause of warped discs, heavy braking then cooling too quickly??

any advice appreciated

cheers

 

[A3-frankie]

something that can warp your discs is using the footbrake to hold the car still at junctions/traffic lights etc.

Because by doing so you are holding the pads onto the disc in one position, causing that part of the disc that is in contact with the pads to cool down quicker.

This can sometimes cause the disc to warp.

Just a thought.

 

[batwad]

I think heavy braking is the main cause of disc warp, though an over-tightened wheel or unevenly tightened wheel bolts can cause it too. Have you been splashing through big puddles lately? Hot brakes + cold water = warping.

Have you checked the discs are actually warped? Could it be the calipers are out of alignment?

 

[Gogs-S3]

never considered the brake calipers being out of alignment, i just assumed the discs were warped, how do i check for correct alignment? It just seems strange that this has happened before, could it be that i need a better quality product that is more fit for purpose?

 

[batwad]

TBH, I don't know Not all calipers are adjustable either, so it might not be that.

Are the pads correctly seated? Any sign of uneven pad wear or disc scoring?

 

[Gogs-S3]

i'm putting my standard rims back on at the weekend so will give the brakes a good inspection when doing that, failing finding anything i will get them checked out and maybe a possible upgrade to something more substantial will be on the cards

cheers mate

 

[AL_B]

I had this problem with EBC Turbo Groove disks (with greenstuff pads), hence why they are not on the car anymore and sitting in my garage wrapped in plastic.

I'd not done many miles on them, about 7000miles, and just commuting miles, no hard driving like I used to do in the "old" days.

One day, hard braking on the motorway, massive judder, thought the car was going to fall apart.

Depending on who you speak to or what you read, brake disks do not warp. Have a read of this:-

http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml

One solution is sanding the disks down, as suggested in the above article. Me and a friend from the TT-forum tried this. It solved it for about 20 mins of hard braking, then...yep it was back. And we made sure we didn't stop holding the car on the foot-brake.

So I think disks may actually warp.

The other thing that happens with the EBC disks, is brake dust sets solid in the grooves and dimples. Waste of time and money if you ask me.

AL

 

[Secret Squirrel]

Using the brakes hard to a complete stop can cause what feels like warped disks.
Did you make sure the hubs were clean when you replace the disks? Anything trapped between the hub and disk can make run untrue.

 

[Roo2000]

I have the same problem on my 1.8T.

I thought it was warped disk's (still might be) but the disk's look brand new and the green stuff pads only look a few months old too.

Also the ABS light sometimes flash's up on the dash, so last night I took her round the block with the ABS fuse removed to see if it was the ABS and it did seem to have gone, so I'm gonna get my mate to plug her in at his garage to see if it is the ABS.

I might be barking up the wrong tree and it probably is warped disks but seems funny it went with the fuse removed.

Just thought this might help

 

[AL_B]

Using the brakes hard to a complete stop can cause what feels like warped disks.
Did you make sure the hubs were clean when you replace the disks? Anything trapped between the hub and disk can make run untrue.

That is another good tip. It is hard to say in my case, they were originally fitted by Awesome Gti...so I would have expected a decent job to be done...but you can never be 100% sure can you.

But like you say anthing trapped or if the disk is not put on evenly, it won't meet the pad evenly and then in time the disk and pad will be worn unevenly.

Yer live and learn as they say.

AL

 

[Ess_Three]

You still got that S3 AL?
I thought you'd have got shot in favour of a 'Box' by now.