Rear brake calliper carrier to hub on my Octavia employs a T57 Torx fixing. I had the appropriate bit, but loaned it out never to be seen again and it now appears to be unobtainable. I'm looking to grind down a T60 courtesy of Mr. Dremel, but worried about making a hash of it so thought I'd ask to see if anyone has a source for the T57. Also a recommended replacement bolt if anyone else has come up against this.

                                                                                                                                                             Regards, John.

You can buy them from the skoda dealer, some vauxhalls use them for the seat belt anchor bolts too.

Are you sure it's not a multi spline bolt instead. Torx has 6 splines - multi spline has 12.

Thanks for the foregoing guys; yes it's definitely a Torx and I've tried a couple of Skoda dealers with no result. Problem is my local dealer 100 miles away is now Arnold Clark. Aaargh.

Could it be a Torx T55 Plus?

Those bolts are absolute pigs to loosen, did mine a few months back when changing the discs and pads, unless the cars up on a ramp it's really difficult to get the required leverage. Mine were definitely multi spline though.

Thanks for the foregoing guys; yes it's definitely a Torx and I've tried a couple of Skoda dealers with no result. Problem is my local dealer 100 miles away is now Arnold Clark. Aaargh.

Any VAG dealer near by?

I replaced my rear discs & pads today,the carrier bolts were M14 multi spline,im guessing the 4x4 is different? 

M14 spline...

T55 & T60 I've seen about, but T57, that's an odd one.

All sorted guys; had to get under the old lady for a proper look and yes! it's M14 splined. I had already done this job using a T57 AS PER SKODA TECH DEPARTMENT. I contacted them for clarification the other day and got a  re-iteration of the T57 story. Possibly a change somewhere, but I was assured my car should have the T57 All sorted now though and all I have to do is the job itself, removing the very chewed looking multisplines doesn't fill me with joy. Thanks to all for offerings.

Get some proper penetrating oil ( Not WD40) such as Plusgas and spray round the fittings a couple of times before you start on the job, day before even better.