no1nutter

iTrader: (1)

fitted a new set of ebc grooved and drilled discs ( not drilled right through ), with ebc redstuff pads. after less than 1k miles the discs had warped to the point of shaking the car to bits, so had them reskimmed. everything perfec for about 500 miles, now they are once again warped to the point of shakin me to bits when drivin. WTF is goin on, are the discs just **** or are the pads too hard, im at the end of my tether and need sum help b4 i find a friendly lump hammer to sort the job out lol!

360ste

iTrader: (1)

When new disc's have been fitted they need a period of bedding in. Where the brakes are not hammered but are allowed to heat up and cool off so work hardening the metal. One of the main reasons for brake warpping is pressure is kept on the brakes once they have got warm thus mishaping the disc. For it to happen twice I would think you may have had a problem with the pads sticking thus keeping in contact with the disc and causing to much heat plus my previous comment.

no1nutter

iTrader: (1)

tbh honest i am very conscious bout leaving foot on brake etc. and just fitted 2 year old 4 pots, the calipers were very free, was more thinking down the line ov the pads mayb been 2 hard a compound.

MrRA

According to this white paper, there is no such thing as a warped disc. Just uneven pad deposits on the disc.

StopTech : Balanced Brake Upgrades

no1nutter

iTrader: (1)

yeh, av already read that and think its a load ov twaddle, the amount ov runout b4 i originally had them skimmed wud equate to about a half the pad depth being deposited in 2 places on the disc and considerin the pads were still like new it just wouldnt add up lol!

stockcar

faulty wheel bearing causing the issue??

TONY-315BHP

No1Nutter- I have the same problem, i have the same style discs (brand new) and the same compound Pads (beand new), I have taken it to a few Scooby garages and they say its fine, but like you i dont like beaking for too long. Mebies the hard racing compound pads just need longer to wear in??

c_maguire

What 360ste says is exactly right. In addition in the distant past I ran some EBC REDstuff pads on my then standard MY00 4-pots and discs. After periods of sustained heavy braking such as an A-road with lots of roundabouts then under heavy braking the steering wheel would shake like the discs were warped. A bit of gentle driving, the brakes would cool down and the problem would go away. When I spoke to a couple of 'brake experts' and mentioned what pads I was using both said the same thing - brake dust from these pads builds up on the disc under sustained heavy braking giving an uneven braking surface resulting in vibration. And judging by the amount of brake dust they left on the wheels and the fact they were worn out between oil changes on the car then I'm inclined to agree. The EBC discs may or may not be OK, but I wouldn't recommend those pads to anybody.
Kevin

The rookie

iTrader: (1)

Most 'warping' is in fact 'thick thinning' of the disc, this is caused when the brajke disc heats up and expands, warping it temporarily, as you stop braking and the pads back off they knock off the high spot on the disc until it cols, a few cycles of this causes the disc to be thicker and thinner enough to cause the shake/wobble/vibration (delete as appropriate) measuring each side in turn would make it look warped, but its not.

This is all down to the pad material/disc material, in general more abrasive pads are better as they are usually harder so knock back quicker and also machine the disc back flat after during lighter applications. The wobble while the disc is deformed can be wuite bad, but the harder pad will at least return it back to usable, other pads it can get worse and worse until you have to bin/skim the discs.

Mintex are bad for this, kevlar reinforced pad (EBC or other) tend to be better, but disc material is also a factor.

Simon

no1nutter

iTrader: (1)

hmmm so looks like im now looking for advice on which pads to use then.