My 69 has developed a knocking apparently coming from the right rear at low speeds while applying the brake. I first took the wheel off and inspected - nothing obvious, brake looks fine, no looseness in the u-joints or anything readily out of place, no signs of anything making contact where its not supposed to. So I got this notion to hang a cheap web cam under the car at various places and see if I could record what was going on. Can't see anything but noise is definitely loudest when the cam is pointed directly at the brake. Mabe somebody will listen and be able to identify exactly what the noise is.

Brake Noise

I next took the rotor off to see if anything was amiss inside the parking brake. Nothing broken, nothing loose. I've never seen the inside of a corvette parking brake before (its my first c3) so I took some pictures. Mabe somebody more familiar will spot something.

I think whoever worked on it before installed the adjuster backwards but I don't know if its related to the noise.

Adjuster

It seems that the front shoe is not being retained flat against the backing plate. And I would assume the wings of the hold down plate on the anchor pin should be flat.

Anchor Pin

Anybody have any insight into this before I put it all back together?

Phil

 

double check your u-joing it looks there is some loose ,,,

 

I reinstalled the adjuster with the correct orientation, bent the wings back flat on the hold down plate, sewed everything back up and adjusted the parking brake per the shop manual. Noise is gone. Lets hope that's all it was and it doesn't come back, but that hold down plate looked pretty chewed up. A shame you can't replace it without dismantling the hub assembly.

Phil

 

Gonna revive my thread because after a while, the noise was back. This time I confirmed that it has something to do with the parking brake. I removed the parking brake shoes from the right rear hub and drove it around the block and the noise is gone.

I need some help tho understanding what is going on so that I can figure out how to fix it. I had read somewhere that there was a possibility that the parking brake shoes were catching on the wheel studs, but I see no visual evidence of that. I had my neighbor walk along side the car and listen and he described a noise like the brake was grabbing briefly and letting go. What is happening during application of the disk brakes that would cause the parking brake shoes to grab?

I checked the caliper, which is a fairly new replacement and all pistons move freely.

 

Sounds like the parking brake shoes were grabbing with each revolution, then popping back in place. Something is either loose in that assembly, or there is an adjustment problem that is causing the P-brake to partially apply,