Warped brake disk

[J12MOC]

I've got that distinctive 'rrrrrrrrrrrrrrrrr' noise during heavy braking which I suspect is a warped disc. No its not the anti lock system! It's not bad at the moment but is getting worse. I've done about 900 miles since its 1st service in early Feb at 5900 miles and nothing was mentioned by the dealership.
The warrantee info in e the handbook is a bit vague regarding brakes...is this likely to be covered ?? Any one experienced this at such low mileage??

[Ikebaddog]

Warped, or out of balance discs, are not mileage related, it only takes one incident of hard braking to a stop, and keeping the brake applied, the brake pad then welds to the disc and deposits a coating, this causes the vibration when braking.

[drofnavi]

If you have a bit of pad pick up on the discs from holding your foot on the brake after heavy braking the discs are probably not warped. You have left material on the disc.

They can be taken off and skimmed / cleaned up on a lathe, provided you are not removing loads of metal from the discs. Any good engineering shop should be able to do this for you, I had a set done recently for £20.

I have successfully done this many times.

[MaverickV12]

Any vibration?

You certain its not the ABS?

[J12MOC]

Thanks John but I'm pretty sure that hasn't happened as I'm aware of the pad bonding potential. After a spirited drive i always let everything cool down before parking, then leave the handbrake off and move the car half a wheel rotation after a couple of mins to dissipate stored heat from the pads. maybe a bit over the top but learned the hard way from various rallycars.
I can't see any discolouration or patches on the discs. Think ill get a clock gauge on them if I can find any steel to stick the magnetic base onto!!

[J12MOC]

MaverickV12 said:

Any vibration?

You certain its not the ABS?

Maybe a very slight vibration through the pedal but its not bad enough to have got to the vibration stage I think? The braking is not hard enough to activate the abs

[MaverickV12]

J12MOC said:

The braking is not hard enough to activate the abs

It does not have to be hard, if the sensor is sending back bad signals, the module will want to correct the problem, by activating the ABS. No ABS lights then?

[Lunablack]

One of the most common symptoms of a warped disc is vibration through the steering wheel whilst braking...

Even light brake pressure could cause distinctive vibration...

[Ikebaddog]

J12MOC said:

Thanks John but I'm pretty sure that hasn't happened as I'm aware of the pad bonding potential. After a spirited drive i always let everything cool down before parking, then leave the handbrake off and move the car half a wheel rotation after a couple of mins to dissipate stored heat from the pads. maybe a bit over the top but learned the hard way from various rallycars.
I can't see any discolouration or patches on the discs. Think ill get a clock gauge on them if I can find any steel to stick the magnetic base onto!!

It sounds like they may well be warped then, I have had a vibration through mine for the last year, only slight, and it hasn't got any worse, planning to renew discs this year (28000 miles) so just lived with it. Not sure it will be covered by warranty, these people are experts at wriggling out of paying up! But who knows....shout loud enough and they are sure to do something!

[Lunablack]

To be fair, a pair of front discs for a Vantage from AM aren't that bad for price.... £280 inc Vat.... Which compares well with Eurocarparts, whom want around £300 quid each


Edited to add... The AM price is for a pair

Edited by Lunablack on Monday 11th March 12:36

[Far Eastender]

If it's mildly damaged, you can have the disk skimmed at a fraction of the cost of a replacement.

[brakedwell]

Have you tried cleaning the discs with hard braking? On a clear road use medium/hard pressure to brake from 75-80 mph down to 40 mph and release the pedal. Do this 6 times without stopping then drive for a while to allow the brakes to cool. It is very important not to come to a stop when the brakes are hot.

[J12MOC]

Thanks for all the useful info guys. Will try the disk cleaning just to be sure, then clock them if its not solved. I have a friendly machine shop so if all fails I'll get them skimmed.