And they've not fixed it :Confused: Only joking.

I suffer from the same problem and have done for years now. I find it's only under light braking i get the problem, if i brake hard(ish) while down changing i don't get judder. It seemingly comes from the passenger side, and on that side the calpier also knocks as it wobbles slightly on the pins (can be moved by hand), i thought it was this movement under light braking that was causing the judder, until braking hard(ish).

Owen Ferry has suggested that it may be a piston in one of the calipers not returning fully. As such, it constantly rubs the pad against the disc, which overheats. After about 3000 miles of overheating, the disc warps sufficiently to cause judder. Hope all will be revealed next Tuesday.

Feel free to use my car Jim when yours is in dock - even tho' you are taking mine into Ollies for the bonnet job as well! One good favour etc....+++

I've got it planned such that a colleague from works picks me up and drops me off on his way in and out of the office, soI can leave mine for the day. Which is lucky, 'cos your car will be in at Ollie's when mine is in at Owen Ferry's! :D

Got the car back from Owen Ferry Automotive a couple of days ago and, fingers crossed, all seems well! :)

They have a gadget that measures the temperature of the discs and Owen had phoned, after they'd taken it for a run, to say that one of the rear discs was hotter than the other three and he was going to investigate. Earlier in this thread, someone said that you can't always tell whether the problem is front or rear brakes.

Now, that's 2 things I like about a garage already: keeps you informed and investigates (doesn't just replace parts). +++

So, as the photos below clearly illustrate, one of the rear calipers had the pads stuck (the rusty ones at the top of the photo) and these were catching on the disc (see the grooves at the base of 2 of the pads).

Another thing I like about a garage: they keep the old parts to show you what the problem was. +++

Owen phoned again to let me know the score and recommended that he replaced the rear pads and skimmed the discs. They have another gadget that does this on the hub to compensate for any 'hub run out' (I think that means it doesn't spin in a perfect circle). He also suggested that I should consider having the front discs skimmed too.

Point 4 that I like about a garage: ask the customer before racking up a big bill. +++

So, I had all 4 discs skimmed and replacement rear pads. Owen took the photo of one of the front discs after he'd skimmed it (another point for Owen! +++) and sent it to me.

Now, I know I have to wait to see if this resolves the problems that were recurring at around 3,000 miles, but I have never had such beautifully smooth brakes - the effect of the skimming is amazing! I drove David's S8 last weekend and thought how nice his brakes were (before mine were fixed), but mine are even better now!

So, full marks for Owen Ferry: nice guy; clean, well equipped garage; brilliant customer service; cares about what he does! :D

Good result Jim! how much did he charge for the whole lot then?

Six hours labour at £39 per hour plus £28 for the pads (all plus VAT). Total £314 incl. VAT.

He'd also checked that the calipers were all working OK so, if this is the cure (and the brakes are better than they've ever been), I think it's money well spent. :)

Good result Jim, fingers crossed for you+++

Yes, there is a scenario that fits as well:

The last set of new front discs and pads were a different make of pad to the first 2 attempts. So, it could be that that the front set-up was fine and it's just coincidence that the problem with the rear pads occured around 3K miles after the front ones were last fixed.

The old rear pads look like a make that begins 'Ape---' but I can't make the full word out. Ring any bells with anyone?

Could be 'Apec': http://www.apec-braking.co.uk/