Im sure its the brake pads rattling as as soon as touch the brakes they stop. Dip the clutch no different. Changes with wheel speed not engine revs, No shack from the wheels. Im I going along the right lines or is this a known fault? Help appreciated
If it was me I'd be worried that something is working loose, could be something as dangerous as loose calliper bolts (I've been there before!). Best get it looked at just in case.
You don't say what car it is but on the Cerbera it is a common problem (on the rear) and can be cured by some silicon sealant on the back of the pads or get some anti squeal pads stuck on between the pad and the piston.
If it was a lose bolt i think id have found that out today... (would be dead) Iv found out how to stop the rattling being a problem,. Open window and foot on the loud peddle. Cant here rattle then.....