Impreza brake noise

[markcp]

Hi,

My 05 WRX doesn't sound quite right when braking from higher speeds. When I brake firmly from motorway speeds, I get a slight vibration through the pedal and a whirring noise until I get to lower speeds (30ish mph). The pads/discs are standard and braking performance appears to be normal.

My initial thoughts were that the pads were worn, but I've checked and they all have plenty of life on them. A cursory inspection of the discs didn't identify any problems either.

Does anyone have any suggestions what could be causing this?

Thanks,

Mark.

[myles1972]

Slight vibration=possible dirt on hubs causing disc not seated flat to the hub. I get the same noise if I bang on, sounds terrible but I think it is heat escaping from the vents?

[ScoobieWRX]

Could be a bit of DTV (disc thickness variation). This is down to pad material being deposited on the rotor over time. Can give vibrations and worse case can feel like the discs are badly warped when they aren't. You don't have slotted rotors which help de-glaze the pads, keeping them nice a clean after every use so normal factory rotors can get a build up.

If the rotors have plenty of meat on them take them to a brake fitters that has a disc lathe and they can skim the discs whilst on the car. The machine takes into account any bearing play and all that in your steering system. I had the fronts done on my Jag and they turned out fantastic. No wobble or anything and still none many thousands of miles down the road.