Squeek From Brakes/Wheels

[John From Edmonton]

I have a 1980 L82 since new. I am not at all mechanically inclined! Recently had my trustworthy mechanic do a lot of work underneath: rebuilt differential, all rubber replaced, new exhaust system, new rotors,brakes, brake lines, left rear axle and on and on. Had the car since new and it was just getting old but only 175,000 km (the winter is hard on it!).

But now I have squeeks from the wheels/brakes. My mechanic is my friend, and trust him completely. He has taken apart every wheel/brake assembly....done whatever has to be done (machined???) to the rotors etc, tried new pads (3 types) etc. But I keep getting this intermittent and very loud squeek.

When I drive, the noise comes from a front and a rear tire....squeek, squeek, squeek (you get the picture). Louder than a low volume on my stereo! Embarrassing to say the least as the car "looks" great, but sounds like a joke as driving by!!!

I vaguely recall hearing of some anti-squeek pin or something. Is there such a thing that my buddy is missing. He does not specialize in corvettes at all and might have missed something really simple but unique to the car. I HOPE!

 

[Eric]

John,

Welcome to the !

My first thought was that you may have bad rear bearings. But you say the noise is front and rear which leads me down the brake path. You said that several different pad types were tried - did this make any change in the noise whatsoever? Also, the rotors were machined - were they done on the car or on a stationary lathe? The floating caliper design of Sharks makes it much more necessary to have them turned on the car so that they are true to the hubs. If there is the slightest variation between the hub and rotor, this can cause the pads to cavetate back and forth on the pins as the rotor spins causing a squeak. This action, in turn, can cause the pistons to cavetate and eventually will cause air to be sucked in and your problems multiply. There are "anti sqeak" devices but most invalidate caliper and pad warranties and they don't solve the problem causing the noise.

Others will chime in with more experience and direction shortly. We'll get your squeaking squelched here.

 

[Eric]

Another quick note - make sure the wheels are torqued correctly. Too much or too little can lead to rotor warp.

Okay, one more thing. Make sure everything spins free and clear of all lines, clips, etc. Spin the wheels with the car lifted to see if you can isolate the source.
- Eric

 

[Vettehead Mikey]

Another quick note - make sure the wheels are torqued correctly. Too much or too little can lead to rotor warp.

Huh? Never heard that one before. Can you explain?

John,

If your mechanic changed out your rotors, he should have measured the braking surface for lateral runout after installion. If runout was more than just a few thousands, then the hub and rotor must be removed and machined as a pair. Very few non-Corvette mechanics are aware of this special requirement. The rotors were never designed by GM to be replaced in the field, only as an assembly with the hub.

This runout might be the cause of your squeak as the high point on the rotor touches the brake pad.

 

[John From Edmonton]

Thanks, I will pass these messages along to him.

John

 

[Culprit]

Here are two other things that I have had cause squeaks that varied with the wheel RPM:

Bad u-joint on a rear wheel - but that was more of a metallic chattering like a punk rock squirrel.

I also had a bad break pad - there was a thin sheet metal backing attached to the thick metal backing. This thin metal had ears that were supposed to hold the pad in place and prevent it from being inserted too far making it easier to get the pin through the pads and caliper. Anyhow, this thin piece of metal had detached from the brake pad and sliped down and was cutting into the hub of the rotor like a knife - causing a squeak squeak squeak as I drove.

But now that I have explained these two other possibilities, they are unlikely to be the problem since you have two wheels affected - I would check the runout on the rotors as was suggested above.

Semper Fidelis,
Culprit

 

[Rudzvetz]

Check the runout of the rotor, if that's within specs slap them brake pads on a belt sander and sand the edges of the pad over a little bit into a radius instead of a square corner. Put some silicone based brake grease on the edge of the pads and on the pad where the caliper piston hits the pad.

-Justin

 

[John From Edmonton]

Continued Squeek from Brakes - 1980 L82

"Also, the rotors were machined - were they done on the car or on a stationary lathe? The floating caliper design of Sharks makes it much more necessary to have them turned on the car so that they are true to the hubs."

HEY IS THIS CONTRADICTORY TO THE QUOTE BELOW?

"If runout was more than just a few thousands, then the hub and rotor must be removed and machined as a pair. Very few non-Corvette mechanics are aware of this special requirement. The rotors were never designed by GM to be replaced in the field, only as an assembly with the hub."

Unfortunately I am green on the mechanical side of things, and still trying to get rid of the squeek....but when I carefully read the two messages that had the above information, they seemed to contradict - am I missing something or is one saying to machine them on the car and the other saying on an assembly???????

Please help!

 

[76okievette]

I am no expert but I am pretty sure what the guys are telling you is that they have to machine as a "set" the rotors and hubs have to be machine as a pair either on the car or off.

 

[drduckster]

You might have him check the parking brake............ just a thought.

 

[John From Edmonton]

But that wouldn't affect the front wheels/brakes' squeeking would it...only the back?

 

[Vettehead Mikey]

"Also, the rotors were machined - were they done on the car or on a stationary lathe? The floating caliper design of Sharks makes it much more necessary to have them turned on the car so that they are true to the hubs."

HEY IS THIS CONTRADICTORY TO THE QUOTE BELOW?

"If runout was more than just a few thousands, then the hub and rotor must be removed and machined as a pair. Very few non-Corvette mechanics are aware of this special requirement. The rotors were never designed by GM to be replaced in the field, only as an assembly with the hub."

Unfortunately I am green on the mechanical side of things, and still trying to get rid of the squeek....but when I carefully read the two messages that had the above information, they seemed to contradict - am I missing something or is one saying to machine them on the car and the other saying on an assembly???????

Please help!

On the car or off the car makes no difference, as long as the two are machined as a pair and the finished rotor surface runs true. Either method will achieve the same goal.

I do take exception the the statement that Corvettes have floating calipers. They don't, they have fixed calipers, which is the source of many of the problems we face.

 

[curtis]

this probably won't apply here, but at the race track I watched a hobby stock guy put the pads in with the metal towards the rotors. Hell of a squeel on all wheels. there are some out there just a few sandwiches short of a picnic lunch.

 

[NorCal Roaddude]

I have an 80 L-82 also and just last week fixed my squeaking problem coming from the right rear wheel.:cool Took the pads out and used a dremel tool to get rid of the thin strip of pad not wearing down, I think it is called overlap. After putting the pads back in, went for a little drive and could still hear a small squeek, but today when driving it I could not hear anything.:Twist Was a simple fix and I would try it before trying more expensive suggestions. On new pads you might have to round off the top inside edge, like suggested above. Good luck as I know that squeak can drive you buggy, You feel like everyone can hear as you drive through the neighborhood.