iblive

My 77 sounds like a bird chirping while driving. The bird dies when I step on the brakes, but comes back to life as soon as I take foot off pedal. I would really like to kill that bird because it makes my car sound like a cheap import. Any easy remedies?

Ooglie Googlie

Sounds to me like a rotor is warped and creating friction as it passes thru the caliper and between the pads.

When you apply the brakes the caliper squeezes the rotor with the pads and the sound dissapears.

If you can isolate which wheel is the culprit, do a runout check of the brake rotor. If not check them all. Which wouldnt hurt.

I wouldnt be surprized if you can actually see the scuff marks on the rotor in question.

CA-Legal-Vette

It could also be worn pads and your "wear sensor" is hitting the rotor.

It shouldn't stop chirping when you press the pedal though.

iblive

Pads are brand new as I replaced them when I swapped out all 4 calipers.

Checking the rotors is a good idea. I had them turned, but the rear ones were marginal. That may be the problem.

vettehardt

It could be a warped rotor like someone said. It could also be uneven pad transfer to the rotor, like the rotors weren't bedded in correctly. Search in the autocrossing section for proper bedding in procedures.

iblive

Thanks for the suggestion, however bedding is isn't the problem either. Been changing my own brakes on my cars for years and I follow the procedure to bed them in. I've put several hundred miles on the car since I did the brake job and the "birds" just started. I probably need to replace both rear rotors especially since the NAPA guy that did the rotors told me they were marginal.

Crash80

U-joints can chirp as well, just something else to think about.....

iblive

I did kind of wonder that as well.... but they shouldn't stop when you step on the brake..... should they????

wcsinx

It's not that uncommon to get a little squeaking out of new pads. Live with it for a few hundred more miles. It might go away on its own.

Yes they can.

jostby

If the pads sit a little loose in the calipers they can rub against the pistons and chirp (or squeek). This is just normal movement and isn't necessarily from warped rotors. You can buy some stuff similar to silicone to put on the back of the pads that prevent it. Sorry, can't remember the name but all auto parts stores carry the stuff. Some high-end pads come with the stuff. Some other brands come with an adhesive backing plate that you stick to the back of the pad that performs the same function.
Jeff.

Crash80

It is a Vette, anything is possible. Actually the reason I went "outside the box" was because the chirping stops when you apply the brakes. Most of my brake issues are reverse of your issue. It very well could be a brake issue, just wanted to bring up other possibilities.