Thumping/grinding sound while braking

I get a rhythmic thumping sound from my right front wheel when braking. The sound gets slower as the car slows, and when very slow sounds more like a grind than a thump. I can feel the vibration through the brake pedal. I’ve had this problem before, and had my wheel bearings replaced – fixed the problem, but after about a year the sound came back. Just had the car inspected and brakes are in good shape (at least those parts checked out by the state inspection). Could it just be that I need to get the wheel assembly tightened up?

(it’s a '99 Honda Civic with about 145K on it, if that matters)

Did the state inspector actually take that wheel off and look at the brakes?

I didn’t watch him, so I can’t be sure, but according to state regs he should have. VA requires inspectors to inspect brakes for:
Worn, damaged or missing parts.
Worn, contaminated or defective linings or drums.
Leakage in system and proper fluid level.
Worn, contaminated or defective disc pads or disc rotors.
(NOTE: A minimum of two wheels and drums must be removed from each vehicle at the time of inspection. Consult the “Official Motor Vehicle Safety Inspection Manual” for exceptions.)

For what it’s worth, I just took it out to get a recording of the sound, because grinding isn’t quite the right word. Maybe groaning. Anyway, I couldn’t reproduce the sound, and I could only feel it very slightly. It’s very cold out tonight. The sound seems to be worse when I’ve been out on the highway or driving long distances, and maybe when it’s rainy/humid.

Definitely sounds like wheel bearings:
http://www.cartalk.com/Radio/player5/player.php?a=shortclip&id=local-cartalk-784891

But again, only while braking.

Non-OEM brake pads can cause brake shatter and weird noises. I’ve had to try a few different brands to find one that did not do this for my '88 Supra. Autozone pads were the absolute worst. I finally settled on Raybestos Ceramic pads from RockAuto.com.

Warped rotors. Retighten wheel lugs to specs just to check. Check pad thickness and condition of rotors. May need resurfacing. But, I keep thinking of over tightening of wheels as it may have come back when wheel was remounted. Had that problem on a rotor on one side that was more worn from a seized caliper. My first Civic calipers was particularly sensitive to seizing and had to clean and lube pins yearly. If not, it exacerbated brake problems. IMO, if the bearings are bad enough to cause braking problems, there will be some excessive play in the wheel. Pretty easy to check.

Wheel bearing make noise all the time, but gets louder when in a turn that puts more weight on the wheel, i.e. when the bad wheel bearing is on the outside of the turn. A bad bearing on a passenger side wheel will get louder in left turns. It does not vary with braking.

I would assume that you have the same brand and type brake pads on both sides of the vehicle. The rotors should match but maybe not. If this started after the rotors were replaced, it could be due to debris caught between the rotor and the hub.

Otherwise, I suspect that the sound is coming from one of the pads. You could have a defective pad that just makes noise, but still wears and brakes normally. You might also have a stuck caliper pin or a defective piece of brake “Hardware”. Thats those little stainless steel clips that go between the ends of the pads and the caliper mount. Maybe one is even missing and no one is noticing.

“I get a rhythmic thumping sound from my right front wheel when braking. The sound gets slower as the car slows, and when very slow sounds more like a grind than a thump. I can feel the vibration through the brake pedal.” dagosa is right. This is a very accurate description of a warped brake rotor. 1 common cause is having the lug nuts over torqued, distorting the rotor. an impact gun can put 3-400 lb torque on a lug nut. Sometimes just retorquing the lug nut to specs, 80 ft lb, can correct this problem. Most likely the rotors will have to be resurfaced, or replaced.

Lugnuts were loose on wheel after tire rotation. 1st time it has ever happened to me. I had shop do rotation. That 1 wheel has had loose bearing for 7yrs now. Has never got worse. Very slight play. 3 other wheels are tight

I hate having shops install or rotate tires. They use a impact driver and not a torque wrench. I always check the torque after I get new tires. I watched a car with brand new rims and tires just pop off as he came to a stop. Needless to say they were shocked as the car dropped to the ground!

I here you. But, loose lug nuts, unless all of them loosened at exactly at the same time, would give you warning. If your wheel falls off, the driver/ owner disregarded the warnings. I am shocked they did not.

Yeah it sounds like a warped disk. Whenever a shop works on my tires, I always re-tighten all the lugs at home again. Also, I always get a note that says to retorque them after 50 miles. If the lug nuts are coming loose all the time, you may need new studs because they are stretched or you may have holes in the wheel that have gotten out of round.