Dsmith

'80 vette 54k miles, garage kept. New calipers and pads. When I drive at low speeds where I can hear the noise reflection, a sound is coming I believe from a rear tire. squeal, squeal, squeal. It reduces as I apply the brake, eventually disappearing. It does not sound like the typical pad wearing particularly when it goes away with braking. I have the stock rotors, if they are warped would they cause this noise with the pistons? I don't think so, they sound came from the old and new calipers. What does a bad wheel bearing sound like? Thanks :confused:

terryrudy

sounds like the problem I have every now and then. To test bearings I think you can jack up the rear and try to move the wheel forcibly left/right and up/down to see if thats wearing. In my case, I think it is the brake pad scratching along the brake pin. I lubed it up and it went away but just this evening I heard it again. Argh! :) I probably need truer rotors to fix my problem. You may have same issue.
good luck
-terry

Dsmith

I agree. I have checked my bearings in the past and things seem adequately tight. I still think it's brake related too. I did greese up the pins though. I will have to check that one again. Eventually new rotors is the ticket. I don't like the thought of the caliper pistons pumping, possibly air. I just bled my brakes solid. I will notice if air comes into play into time. At least the stainless sleeves will help.

dually4wd

Check out your u-joints too; a dry joint will make a sound like that.

Dsmith

U-joints, didn't think of that. Will check. The fact that when I apply the brakes I can control the resinence of the sound, eventually eliminating it, it would lend me to believe that it's a rotor to pad problem. Warped rotor possibly. I am going to inspect all of this Friday while enjoying a cigar. :smash:

Dave68

Check the rotor runout with a dial gage. The runout shouldn't be more than a few thousanths of an inch.

GaryS

When you put the new pads on did you remember to apply some anti-squeek material to the pad? Since the pad "floats" on the rotor and the piston of the caliper rests on the pad, there can often be a bit of squeeking. If this squeeking diminishes when the pedal is lightly pressed you may have nothing more than pad/piston interference. Most pads sets come with this anti-squeek material, but in a pinch I place a very tiny bit of wheel bearing grease on the surface of the pad, where the piston comes into contact with it.
Gary

Dsmith

Yes I did put plenty of that orange gunk on the backs of them. I pulled the pins off and greased them up. It helped a bit. It is definetly pads to pistons/caliper problem. Use a gauge? I pulled the tires off and while jacked up, put the car in drive and inspected the rotor assembly. I could visually see the pads float back and forth slightly. Yuck, maybe about .05" :smash:

Dave68

If the sound came from both the old and new calipers, I would have the rotors turned. .05"? That is way too much!

chevyman

I had a similar problem and it turned out that my emergency brake spring broke and was causing a squeel.

DADS8T2

My 82 does exactly the same thing. Rear driver's side. Although the brakes were relatively new, I pulled all the wheels looking for it . . . the noise drove me nuts. I had a mint car that sounded like a junker. Finally took it to the local Chevy dealer. The "brake hardware" (read that pins) was in need of lubrication. $60. End of problem . . . until last weekend--so it lasted a little over a year. Go figure. The car hasn't even been wet in all that time. This time I'll do it myself.

Tomi72

I had the same symptoms, squek squek from drivers side rear which would go away when pushing the brake pedal. I also have new calipers and pads.

In my case it was excessive rotor runout. I had about 0.02", manual says 0.005" max. I used shims cut out of a coke can (tip from this forum :))between the disc and hub and got the runout to about 0.003". Fixed the problem 90 %, I think I have the same situation (though not quite so bad) on the passenger side also.

rgds Tomi