Astra brakes ??

Did you check the pads all around could be them ?

Were they pattern pads ? I had a similar problem on an escort which was cured by genuine pads. Obviously the discs need to be in good nick

Could be ABS pump as it kicks in when braking hard. I can't remember what car it was now but I drove one that made a horrible grinding metal to metal sound as the ABS pump kicked in. Try temporarily removing the ABS fuse or disconnect the plug and see what that does.

That's about half worn.

That kills the power steering on these, though. Just a heads up.

Is it the body kit hitting the ground? :-)

ABS usually make a vibrating sound.

ABS can sound like a grinding noise on some vehicles. Also I'm sure astra's relied on EBD (Electronic Brakeforce Distributiion) for the rear brake compensation, which essentially means the ABS on the rear brakes will kick in under heavy braking. Provided there's plenty material on all the pads, I wouldn't be too concerned.

Pads don't normally need changing until the friction material is around 3mm thick.

You could try filing a lead on the pads to see if it makes any difference, but failing that I'd suggest replacing the pads and discs with OE ones, unless you know for certain that they are fitted at present. If the discs have been replaced by pattern ones, it could be that they are incompatible with the pads, or vice versa. Mike.

Thanks to all for your help

We are going to have a blitz on the brakes to try and sort this, as this is a safety issue we will change all discs, pads fluid etc (relativley cheap to do) so will not hurt too much. If its still there will check ABS....."now where did I put my old AVO meter!!" Will let you know the outcome.....ttfn.....Alistair

Really? Apart from not having to worry about them for a while, what does 3mm give you that 2mm doesn't?

very thin pads can overheat and fade more easily than thicker, I have also seen very thin lining fall off the backing

Less chance of failure due to fade is the main reason AFAIC. There is also the point that pads and discs don't wear evenly, and pads that are 2mm thick where they're visible, might be much thinner on the inner side, and is it really worth trying to get a few more miles out of a set of pads, when it might compromise safety? After all. How much is a set of pads. Around £30, for pads that'll last for