impreza humming noise when braking!

[rb5230]

i had a humming noise when i used the brakes heavily which i thought would be cured with new discs and pads as the old ones were pretty knackered, anyway i replaced all the discs and pads on the whole car and got the brake fluid changed at the same time. the noise however never went. it is like a winding humming noise which of which the tone changes as the speed decreases, it only happens under heavy braking.

any ideas? thanks

[FlickingTheVeeS]

My "clasic" shape sti does the same, someone told me it was the grooved discs.. I am interested if anyone else's does it, would it be the abs?

[rb5230]

http://www.pistonheads.com/gassing/topic.asp?h=0&a... humming noise under heavy braking!

it would seem so.

[BurgerKing]

I had this with Black Diamond grooved discs on my classic wagon (when braking heavily), you didn't really feel it in the brake pedal but the noise was quite comforting for some reason. I do miss that car :-(

[rb5230]

yeh i have heard numerous people now saying it is the grooved discs, so i feel much better now.

[ScoobieWRX]

Doesn't matter what the car is, all grooved discs when they get hot under heavy use do the hum.

[rb5230]

ScoobieWRX said:

Doesn't matter what the car is, all grooved discs when they get hot under heavy use do the hum.

its quite loud though.

[ScoobieWRX]

Mine do the same, and you can really hear them in the car when they're getting really worked. Under normal operation they're pretty quiet. That's normal.

[Evil.soup]

My discs are 20 grooves and make a hell of a racket under heavy breaking, sounds like something windeing down. I also get low speed brake squeal to compliment the humming due to the Mintex pads!! I dont mind it though, it sounds a bit WRC!

[DocJock]

It can also be caused by pad resin deposits on the disc surface, even on plain discs.

[Scooby P1]

ScoobieWRX said:

Doesn't matter what the car is, all grooved discs when they get hot under heavy use do the hum.

I have the official Prodrive 330mm Alcon upgrade and the discs have a few big grooves. When getting stuck in to the brake pedal there's a really noticeable hum, almost like the engine is making a sudden slowing noise but agree with the consensus here that it's the brakes. Begun to quite like it and it's when they are really starting to perform that it happens!