Hard braking causes humming noise in the back

Hello all,

I’ve been recently having a problem with my rear brakes that seem to be causing a high pitched humming noise when I apply the brakes after driving at 50 km/h.

The best example is when coming off the highway and coming to a stop. The noise occurs for a second or two right before the car comes to a full stop. No vibration or pulling of the steering wheel of any sort.

Car is at about 10,500km so definitely don’t think the brake pads need changing.

Full disclosure I was in a minor fender bender recently (hit from behind while stopped) not sure if that might have efffected my brakes in some way?

Help would be much appreciated!

Follow up to this. I went to the dealer and they said my read pads were rusty (they said this was due to the car sitting which is weird because it rarely sits for more than a day). They resurfaced the rotors and the sound went away.

Now a couple weeks later and the sound is back? Any ideas what this could be from? Looking the dealer service receipt it said my brakes were runout, could this be caused by something else hence causing the humming/squeal to come back?

You're not driving your car hard enough, basically.
Modern brakes have a high metallic content. It's why they stop so sharp, etc... Downside is if you drive it around town, are easy on it, etc they can basically glaze, and that's what you're hearing. This will also be the first few stops on a wet or dewy morning as well. If the sound comes back, do a hard stop or two on the highway and it should help. If that doesn't work, then back to the dealer. But that's what it sounds like based on my own experience in the industry.

Don't know much about this topic, however I though glazing was due to braking excessively hard and the brakes overheating?

I'm not shy with the brakes by any means, my girlfriend usually complains about my braking habits

I brought it back to the dealer the other day and they claim they could not hear it but it is definitely still there... It was a little lighter when I got it back though, so I think maybe you are right? I'm assuming they drove it around and probably jammed on the brakes a couple times.

Follow up question is why should I have to slam on the brakes every day in order for the brakes not to become glazed? Feels a little excessive of a task for a car with less than 15,000 kms on it?