Loud humming when heavy braking

[Volvoturboman]

Hi all, I've notice over the past couple of weeks that under heavy braking on occasion my brakes are humming quite loudly. This is not something I can show anyone as its extremely intermittent. I could go a day or two with nothing and then it could happen twice consecutively. Brakes seem fine although there is a shake when braking suggesting possibly a warped disc but would a warped disc cause this noise? Also I had a new coil fitted recently for PSV although I reckon that should make no difference to the brakes.

[Ares]

Could be warped disc or those brake pads,did you check the condition of the pads?
My brakes do humm sometimes but nothing too loud.

[trufflehunt]

We wouldn't be talking here about the ABS coming on as you heave it down from 115mph on the local by-pass..?

[Volvoturboman]

No to ABS there's no kick back at all and both abs rings were replaced 6 weeks ago for PSV. Pads are well worn now after a look. I take it I'm looking at new discs and pads then. This taxi life is so hard!!!

[crackpotterpig]

I did notive a "hum " from mine the other day actually first time i have heard a noise like it on any car when braking.If memory serves me correctly it was below 30 mph and not really harsh braking.
I am not too concerned as I serviced it in april and know all the pads /discs are ok I think it may be abs pump related as the noise seemed to make a low frequency vibration from front of car...............just another one of those faults that we let "develop" I think it maybe the newness worn off at 14 years old and 174k later!!