Warped Discs

[GrumpyTwig]

So I'm pretty sure one or both my front discs are slightly warped, originally thought it was my wheels (I know one has a very slight buckle but having taken them to a proper alloy wheel specialist they don't appear to be very bad at all, certainly not to cause any issues you'd notice) swapping back to my originals I still get vibration braking at high speed.
I think my first day at Oulton didn't do them any favours and I maybe didn't let them cool off as well as I should .

Only option is to replace them right? It doesn't annoy me too much but any harm in leaving them?

 

[N0ddie]

So I'm pretty sure one or both my front discs are slightly warped, originally thought it was my wheels (I know one has a very slight buckle but having taken them to a proper alloy wheel specialist they don't appear to be very bad at all, certainly not to cause any issues you'd notice) swapping back to my originals I still get vibration braking at high speed.
I think my first day at Oulton didn't do them any favours and I maybe didn't let them cool off as well as I should .

Only option is to replace them right? It doesn't annoy me too much but any harm in leaving them?

I had a braking "imbanlance" on my Corsa. Only noticed it when braking hard. Vxl did suggest I replace them but a year on they no longer "vibrate".

Seems as though they sorted themselves. Dunno if warped discs will be the same though?

 

[BenW]

I've done a fair bit of research into this as I have the same problem.

It's pretty much impossible to actually warp discs, even on a race car. 99% of cases that feel like warped discs are actually a case of pad deposits on the disc.

Pad deposits are normally caused by coming to a complete stop with hot pads and holding the brakes on, letting the pads 'melt' onto the disc.

You may be able to remove the deposits by doing the bed in procedure (lightly warm the pads then do ~10 heavy stops from 60mph to 10mph only allowing very short times for the pads to cool between stops). If you can't remove them like this then you may be able to remove them with wire wool and some brake cleaner.

The good news is you almost certainly don't need new discs, bad news is that your driving style is probably causing the problem which is a bit difficult to change! If you're using aftermarket pads then swapping to standard will help or a different aftermarket pad may also help.

See the stoptech website for more info, good article from people who know what they're talking about:
http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml

 

[Arran]

I never leave my foot on the brake when stopped, I always put the handbrake on. When we were going for it in Wales a couple of weeks ago, I switched the engine off and left it in gear without ANY brakes on at all.

 

[GrumpyTwig]

I've never from memory held it on the brakes when they're hot (or on the handbrake for that matter) always in gear, I know better than that.

Thanks for the link Ben I've seen that before but never actually read it I'll give it a go and report back, pads and discs are all standard btw.

 

[Mike Roberts]

You also get deposits when you've overcoooked the pads and they've leeched their resin onto the discs. It'll come off with rebedding.

 

[Maz]

Were you using your handbrake at Oulton Tom ?

 

[GrumpyTwig]

Were you using your handbrake at Oulton Tom ?

No it's the fronts that are the problem anyway,was going to try bedding them again today but having to wait in for some oil I ordered :sleep:

 

[Maz]

Ah LOL good luck