Humming Noise - Rear(?) - Stops when Brake Applied

Hey, I have a humming Noise that (seems) to be coming from the rear of my Taurus (98). The Noise does not start right when i begin driving but does usually occur by the time I reach my destination. If driving for a long time the humming will get worse but then may dissapear if driving even longer.

The noise ALWAYS 100% stops every single time I so much as touch the Brake pedal. It also seems to change magnitude, or stop when i change direction either to change lanes or make a sweeping turn.


Considering a Wheel Bearing based on other readings around the web but any other opinions greatly appreciated.

If the noise goes away with brake pressure, its not a wheel bearing. Sounds more like you've got dragging brakes on the rear. Do you have drum brakes on the back? If its making that much noise, they will get very hot (the drums) and could possibly be warped out of round, or could have deep grooves worn into them from the pads, which could rub when lateral force is applied (when taking turns). I'd take the drum off (if you can, you may have to adjust the pads in before being able to even pull the drum off) and have a look. Let us know what you find.

They are disc brakes and there are no grooves in the disc, they are smooth. The noise is not specific to making turns, its just a general noise but it does seem to be specific to the rotation of the wheel as one time in heavy traffic when i was going real slow the magnitude of the noise would change in pattern as the wheel spun.

But again, definately no deep grooves, all 4 are generally smooth to run a finger accross

I've had a similar sound with drum brakes, when I hit the pedal it went away. Replacing the wheel bearing fixed it.

I would not rule out the wheel bearing yet, but I would first closely inspect all four rotors and brake pads. Take the calipers off and remove the pads, inspect them all for any foreign material as well as any large pieces of friction material in the pads. There may be a large piece of some material in the friction lining that is setting up a resonance, but when you apply the brakes it gets dampened by the rotor.

Also look for any rust lips on the outer or inner circumference of the rotor braking surface. I've seen where as the friction material wears, it starts to make contact where it didn't used to. You can usually spot this as a polished spot on the edge of the rust lip. Usually the most reliable solution is to get the rotors machines/turned just enough to take the rust lip off and make sure the rotors are not warped.

-Rod

Did you find the answer to this problem? My car has the same issue.