My 69 has developed a noise apparently coming from the right rear at low speeds while applying the brake.  Its like a faint knocking sound.  My brother says he could feel it when sitting in the passenger seat, like somebody knocking on the underside of the car.  I've taken the wheel off and visually inspected, everything looks good, caliper, rotor and pads all very new.  Doesn't seem to do it all the time, but mabe just sometimes its more or less than other times enough to notice.  Before I tear into it further, thought I'd call upon the collective experience of the forum.  Lots of previous posts on brake noise, but none described as mine and I've never had such a brake problem before on any car.  What to look for? pdupler2008-09-14 08:21:30

OK this will sound wierd but it might be your problem. I ran into this on red-70one's car. He had the same thing only made noise when there was two in the car and it sounded like knocking in the rear. When we looked we found the drive shaft was hitting on the tunnel and you could see the rub marks. now here is the wierd part. It turned out to be the body mount shims had worn and let the body drop just enough. Check it out. Who knows!

I'm still stumped.  I can't find any evidence of the driveshaft hitting anything.  I even clamped a web cam to the bottom of the car in various places, but it doesn't show anything obviously wrong.  The noise is definitely recorded louder with the cam pointed directly at the right rear wheel tho.  Listen for yourself and mabe somebody will recognize the noise and know exactly what it is.

Brake Noise

Phil

I can't watch the video here....dial-up sux...
A couple of things come to mind from the description, tho...
Check the back side of the wheels for wheel weights that may be hitting on the caliper, or the rear spring. It happens sometimes.
Also, check the brake pad retaining pin(and the pads themselves) for wear. This could let the pads flop around in the caliper, and cause a clunk/knock when the brakes are applied.

Does the noise/knock still happen if you apply the parking brake at slow speed, instead of the service brake?

One last thought...it could be the front trailing arm bushing, but...they will normally clunk under power, or under deceleration.

Did you point the camera (and the mic) at the rear end?  Have you checked your fluid in the rear end and if it is a limited slip have you changed out the fluid and put the GM Limited Slip fluid in?

71Shark had a situation where the bolts inside the rear end had come loose and would get hung up, causing a clunking type noise.

When I changed the u-joints on mine, the needle bearings were powder and allowed the shaft to move around in the cap causing a popping type noise.

Took the rotor off to see the parking brakes.  Not having seen the inside of a Corvette parking brake before, y'all tell me if anything looks suspicious.

adjuster


anchor pin

None of the springs are broken or loose.  According to the book, the adjuster was installed backwards.  I can fix that, but don't know if has anything to do with the noise.  The front pad doesn't seem to be retained against the backing plate.  On the anchor pin is something described as a hold-down plate.  I would think the wings on that plate should be flat.

I would check the half shaft u joints very close. That klunking sound comes around pretty quick. There has got to be some marks on something under the car with that much noise. Good Luck.

The "wings" should be flatter than they are....

I got to see the video this morn here at werk....check that wheel weight. The noise is happening every time that weight passes the caliper....best I can tell, anyway.