Page 1 of 1

Brake shudder.

Posted: Sun Dec 26, 2004 8:27 am
by Smeegles
Hi
My S has slowly developed a very sligh brake shudder when i hit the front anchors.
As far as I know the front pads haven't been replaced and may still be the originals (56000kms on the odo of which I have done 26000)
Could it be one of the disks or something else?

Posted: Sun Dec 26, 2004 8:56 am
by Paul
Smeegles,

Try holding the front disks and see if you can move the disks up and down (i.e. in the vertical plane) against the retaining bolts. The wheel posts onto which the disks are bolted do tend to wear... If you can move the disks by hand, that would be your problem. You can buy some wavy washers from your neighbourhood BMW dealer and fit those behind the collar that the disk bolt goes through to cure this particular problem. They are a standard BMW part, and can be found on the parts 'fiche' for the front wheel and disk components.

HTH

Paul

Re: Brake shudder.

Posted: Sun Dec 26, 2004 10:38 am
by Jason M
Smeegles wrote:Hi
My S has slowly developed a very sligh brake shudder when i hit the front anchors.
As far as I know the front pads haven't been replaced and may still be the originals (56000kms on the odo of which I have done 26000)
Could it be one of the disks or something else?
Could be what Paul says... or a warped disk. I've had a couple warp slightly. They'll show up by slight pulsing through your hand at very low speed very light braking, and judder at high speed. If it judders a lot then I'd say is a warped disk cos with the worn posts, once the brakes have clamped the disk they're fine and don't judder (in my experience anyway)

If you go for new disks DO NOT LET MOTORWORKS SELL YOU PFM CAST IRON ONES. They're cheaper and work fine but rust 2 seconds after water hits them and make cleaning the sh*t off the wheel a f'kin nightmare!

Jason

Posted: Sun Dec 26, 2004 3:12 pm
by PBBoxer
<<Agree with Jason
I had a set of disks and calipers replaced on Warranty earlier this year. It started with a gentle vibration, but worsened very quickly to a harsh shudder....and to add insult to injury the front caliper seized and nearly threw me over the front. The dealer said the caliper had been sticking and the disk had overheated and warped... all i know it when it started, there was a gentle vibration just as the original post decscribes

Posted: Sun Dec 26, 2004 4:30 pm
by Boxadog 2000
Deffo a warped disc.

If the bike is under warranty get the dealer to check it out if not, remove each disc and lay a disc on a sheet of glass and try and slide a feeler gauge under it at 4 or 5 different points.

Start with a .005" if it does slide under the disc at any point then it is bolloxed.

You can skim them down by a couple of thou but it is rarely worth the time effort and money.

Posted: Mon Dec 27, 2004 6:29 am
by Smeegles
Paul wrote:Smeegles,

Try holding the front disks and see if you can move the disks up and down (i.e. in the vertical plane) against the retaining bolts. The wheel posts onto which the disks are bolted do tend to wear... If you can move the disks by hand, that would be your problem. You can buy some wavy washers from your neighbourhood BMW dealer and fit those behind the collar that the disk bolt goes through to cure this particular problem. They are a standard BMW part, and can be found on the parts 'fiche' for the front wheel and disk components.

HTH

Paul
Thanks Paul I did as you said and sure enough the left hand disk is doing what you said.
Now to go and get those washers.
Nick.

Posted: Mon Dec 27, 2004 2:54 pm
by Boxadog 2000
The BMW part number for the genuine washer is M34.11.7.661.877
hope this makes life easier for you

Bob