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Discussion Starter · #1 · (Edited)
My brakes (esp rear) have always had the tendency to squeal. Ok.. so yeah we all know by now why the Volt is more susceptible to this.. fine.. I get it.

But my problem is more significant than the norm.

After about a year, I had a recurring squeal so had the dealer look at it.. the "chamfered" the rear disc and it went away for a few months, then came back. No rocks, etc.

Took it to Les Schwab, they couldn't do anything either, said it all looked great. "brakes look brand new, but hey do squeal" was the exact quote.

Now, at 38k - every stop or slow roll is painful. Backing out of the garage every morning, my nrighbors must hate me, it's one long squeal. That last little bit of travel when the brakes kick in after regen typically from 3-4mph to 0 is terrible. It's worse when I'm fully charged, since the regen can't kick in as much.

Every day I leave work (charged up) and the people eating outside at the restaurant across the street ALL look up to see the squealer car. Embarrassing. Same in parking lots, drive throughs etc...

When I pull away, It squeals intermittently, like the spot is coming around on the disc.. then constant when I have to press on the brake pedal.

I thought maybe a sticking caliper or something, but all disc temps are the same after a long drive (barely higher than ambient since we don't use our brakes much).

It's really mostly in one of the rears. I do use the parking brake, and do not drive the car hard at all. Does anyone have any idea of anything I can do? Buy a new rotor, or those little dampener thingies? It's not normal and the dealer just wants to shave the disc down again but I don't think that's it.

2012 Model Year.

Any insight is appreciated.

Thank you,
Brant
 

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Have you tried putting your vehicle in neutral and coming to a stop that way once or twice a month, from around, say 25mph? The brakes will feel spongey, as only the friction brakes are used in neutral. Doing this will likely keep your surface rust off and eliminate squeal.

Just a thought. I've done this on rare occasion when I feel like my brakes are wet/ineffective after going through large puddles for example.
 

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Have you tried putting your vehicle in neutral and coming to a stop that way once or twice a month, from around, say 25mph? The brakes will feel spongey, as only the friction brakes are used in neutral. Doing this will likely keep your surface rust off and eliminate squeal.

Just a thought. I've done this on rare occasion when I feel like my brakes are wet/ineffective after going through large puddles for example.
I agree, I used to do that with the Prii to get rid of surface rust.
 

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Even though the dealer has looked at the brakes, it sounds (sorry for the pun) like one of the anti-squeal thingies - a metal or teflon wafer or shim that is sometimes placed between the back of the brake pad and the brake piston - is missing.

http://www.popularmechanics.com/cars/how-to/maintenance/4317748

Good luck.
 

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Another cause of constant squeal can be if the pads are not glued to the calipers, or have come loose. They usually come with a special glue just for this. It might be worth checking for this.
 

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Discussion Starter · #6 ·
Have you tried putting your vehicle in neutral and coming to a stop that way once or twice a month, from around, say 25mph? The brakes will feel spongey, as only the friction brakes are used in neutral. Doing this will likely keep your surface rust off and eliminate squeal.

Just a thought. I've done this on rare occasion when I feel like my brakes are wet/ineffective after going through large puddles for example.
Definitely tried that.
 

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Huh. It certainly isn't an inevitable characteristic of Volt brakes - in almost three years, I don't think my brakes have ever squealed. (So it's fixable, one the source is identified.)

If you press the brakes firmly, does it get worse? Or does it go away?
 

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Discussion Starter · #8 ·
Firm presses on the brakes makes it go away.

Just cruising slowly down the side of my building without pressing either pedal, it squeaks like a truck backing up. Then a long squeal when I gently apply the brakes when entering the road. At higher speeds I can't hear it, then when slowing from faster speeds back down to <10mph it's not there again until I brake to go slower.
 

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I would try a new set of pads. When you say they "chamfered the rear disc", that doesn't make sense. Maybe they chamfered the rear pads(which means the outside edges of the pad are thinner than the middle). Possibly a pad of slightly different material would work.
 

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Firm presses on the brakes makes it go away.

Just cruising slowly down the side of my building without pressing either pedal, it squeaks like a truck backing up. Then a long squeal when I gently apply the brakes when entering the road. At higher speeds I can't hear it, then when slowing from faster speeds back down to <10mph it's not there again until I brake to go slower.
Squeaks that go away are something loose that can vibrate - a brake pad being the most likely candidate. If you're hearing a squeak without hitting the pedal, something is definitely dragging where it shouldn't.

Do you have an infrared thermometer? You might be able to figure out which corner by measuring the temperature of the brake discs after a drive.

Or you could put the car up on a jack and see if anything is loose (remember to check both sets of pads on each wheel.) Since it squeaks some without the brakes, it could be something jammed under the dust shield that doesn't belong, too (but I think that is less likely since applying the brakes changes the sound.)
 

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I would get new pads. I had a BMW 318ti that would squeal like mad if you braked anything less than neck jarring. I had pedestrians comment on it a couple times. Nothing was physically wrong with the brakes, just the pad material. New brakes totally fixed that and didn't hear it again.

I notice the rear brakes on the Volt see very little use with the regen braking and the fact the car is pretty front heavy. This could cause them to glaze up. You could try burnishing them. In a safe area do 1 or two 70-0 mph stops at max stopping power (triggering ABS), and see if you can brake up any glaze that has formed, otherwise new pads and turning the rotors might help. Less safe would be to drive backwards at 15 mph or so and do some hard stops, but it would put more strain on rear pads and I wouldn't want to see you back into something at that speed.
 

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My brakes (esp rear) have always had the tendency to squeal. Ok.. so yeah we all know by now why the Volt is more susceptible to this.. fine.. I get it.
I didn't know the Volt is susceptible to this. The brakes on my 2011 don't squeal. I have 50k miles. I'm curious as to what makes yours more susceptible and mine not? Mine's simply happier? :)

Regarding turning the rotors, the rotors will quickly rust, no more shiny. Just fyi.
 

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I meant to turn rotors to brake up any glaze on them and make a new surface for the new pads to go up against (this might not be necessary). Rotors always rust within minutes of any moisture hitting them, they are high carbon steel. If it rains and I go out to my car in the evening, the rotors will have rusted.
 

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Even though the dealer has looked at the brakes, it sounds (sorry for the pun) like one of the anti-squeal thingies - a metal or teflon wafer or shim that is sometimes placed between the back of the brake pad and the brake piston - is missing.

http://www.popularmechanics.com/cars/how-to/maintenance/4317748Good luck.
+1

Back in the day when I did my own brake work, I rediscovered that squeal was most often caused in disc brakes by the vibration of the piston moving laterally against the back of the pads. The anti-squeal teflon clip/spacer eliminates that. If not available, the anti-squeal compound replaces that function.

The rotor may initiate the action, but the noise is from the piston/pad interaction.
 

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Rotors always rust within minutes of any moisture hitting them, they are high carbon steel. If it rains and I go out to my car in the evening, the rotors will have rusted.
OE Volt rotors should not do this. They are specially treated to resist this. That treatment however may only go so deep on the rotor
 

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Discussion Starter · #19 ·
I tried to capture it on video when I left for lunch, but of course, it didn't do it. It DID squeal after I started braking though, but it didn't do the squeak squeak squeak by itself that it normally does. I'm not crazy!

 

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Yeah, mine definitely doesn't do that. If the dealer can't help, maybe a shop whose expertise is brakes can help? Aside from the pedal blending and the hydraulic accumulator/pump system (and the coating on the discs) Volt brakes are like any other modern car - sources of squeaks likely are, too.
 
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