Brake Judder on new discs

[jamesr]

I have just fitted my new drilled discs and they are CRAP at the moment....

There is no bite to them and from high speed +60mph they just judder when you touch the pedal.

Do they take a bit to bed in?

[glynn]

you need to take it easy for about 200-300 miles so try and avoid any heavy braking or you WILL warp the discs

[jamesr]

Fitted on Wednesday and already done 400 miles - but no improvement

[parapaul]

AFAIK it's more to do with the pads than the discs - what pads are you using?

[jamesr]

I didn't fit new ones cos only fitted 2 months ago, they are police spec pads.

[GARY3306]

When you say 'judder' can you feel the pedal pulsing under your foot? ie moving rapidly up and down as you brake? If that is the case then you may have a warped disc (unlikely being that they're new, but not impossible), or more than likely, you have excessive runout on one or both discs. This would require you to remove the discs again and clean up the mating surfaces. As for the brakes being crap, if you have excessive runout, the pads will be being knocked away from the disc, by the disc if you follow me. Depending on the pads being used depends on the length of time they need to bed in well with the discs (some friction materials are harder than others).

[frazejax]

I didn't fit new ones cos only fitted 2 months ago, they are police spec pads.

Excuse my bumbness, what is police spec?

[plasma]

a nice soft pad with a lot more 'feel' to it under braking than standard aftermarket pads. Normally used on police vehicles. Think they are mintex pads?

[SYMON]

Your old pads, 2 months old, had worn to surface shape of your old discs.

So your now, nice flat new discs have uneven pads on them.

Really bad practice, new discs and new pads, always at the same time.

[gtr1000]

Your old pads, 2 months old, had worn to surface shape of your old discs.

So your now, nice flat new discs have uneven pads on them.

Really bad practice, new discs and new pads, always at the same time.