I cannot for the life of me figure out what is causing this noise. It comes from the rear end of my car, and only when the brakes are applied. I've rotated the rear tires up front, but the noise remains in the rear; so not tire/wheel related. Last night I completely took apart the rear brakes on both sides, nothing was abnormal, pads are good (just replaced all rotors/pads a year ago), rotors look good, no uneven wear and nothing lodged in the brakes to cause grinding. The slides still moved nicely, no broken boots or anything. No stuck calipers (wheels spin freely without brakes applied).



The sound isn't a constant grinding when braking, it's a one per wheel revolution grind. Like there's something sticking out on just one part of the rotor that grinds with each revolution. It sounds constant when braking at high speeds until I slow down then you can hear it grind with each revolution until coming to a stop.



This would have to be brake related right? Is there anything suspension related that would cause this? I'm at a loss at what to check out next.

 

What happened to me once was the dust shield got bent and the rotor was hitting it. Maybe check that.



Sounds like you did a pretty thorough job. Describe the grinding. High pitch, low pitch. Rough like it's really digging into something, or light like it's just barely touching.

 

If it's once per wheel revolution, there's something jacked up on one spot. If it's only when the brakes are applied, it's the brakes. I'm guessing you have a ding or some corrosion or an area of heavy scratches or a squirrel bone or SOMETHING going on with one of your rear rotors and/or calipers. Check carefully.



Long shot but... I know my front brakes (I have drums in the rear) have a big ridge all the way around from wear, and it's rough and rusty all the way around the outside rim of my rotors. If that rust got a little thick in one spot it could rub somewhere.

 

Try putting a brick on the pedal and spinning the wheels with the car jacked up? But +1 for heatshield.

 

Thanks for the input guys. I actually thoroughly checked the rotor heat shields all around with a flashlight. But not even close to touching anywhere; and they don't flex enough to be able to touch it seems. I thoroughly inspected the rear rotors too. Still look practically brand new. Didn't see any hotspots or debris or anything anywhere on the rear rotors, inside or out. And they haven't worn enough at all to get the depth wear line.



It's a low pitch grind, like it's moderatately getting stuck on something with each wheel revolution. Good idea, I may put my wife in the drivers seat and jack up the rear and spin the wheels with her hitting the brakes to see if I can pinput it. Thanks guys.

 

Also, have we checked to see if the wheel bearing is bad? I've had the rears go bad on the tib so it is possible. Jack the car up and try to wiggle the wheel. It's worth a shot.

 

Good point, I'll check that out when I'm working on it next. Hopefully that's not the case, never done a wheel bearing change before!

 

Unless I am greatly mistaken, the wheel bearing/hub is a replaceable assembly. Unbolt the assembly, replace with the new one. WAAAAY easier than the fronts.

 

That is correct. The fronts are a pain and have to pressed in and out of the knuckle.

 

I have same problem, did you find out what was it?