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Discussion Starter · #1 · (Edited)
I need your feedback and please review my Video. My 2012 Volt makes a lot of excessive brake pedal noise. This is loud enough the I can hear it over the radio. Since I've had my Volt for about 5 months now the noise is like en-grained in my head and I cringe every time I hear it. I have test drove plenty of Volts and they don't make this noise this loud. I tried having the dealer fix it but the response I got was that the noise can vary from car to car. It finally got to the point that I just wanted my car back (over a week in the shop). See below for my story and timeline. Here is what I know:

1.) Only makes the noise when the car is on or has power to it
2.) Louder after long drives
3.) Most annoying during 3 point turns and when backing up and going forward. I perform 3 point turns every day our of my driveway.
4.) If I pump the brakes a few times an additional buzzing noise will occur last a few seconds then shut off (I don't really have an issue with this but it is an observation)
5.) It is not as loud when it is in park vs Reverse, Drive or L
6.) When I pump the brakes I can feel a springy vibration in the pedal

Does anyone else have similar experiences?

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Ok here is a video of the noise. I had to use an old underwater video camera so it doesn't seem as loud but it is. Please turn up your speaker volume. The noise is also hard to tell where its coming from. I think its from inside the engine compartment.

http://www.youtube.com/watch?v=7WvyrmHxISU&list=UUlaXZgLmh4KxUADubj4i1YA&index=1&feature=plcp

I've added another one that has better sound here:
http://www.youtube.com/watch?v=oBWK7QLEAk4

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Here is my story so far:

Ever since I bought my car I noticed the brake pedal noise was very loud. It's a springy metal bouncing noise. I thought at first it needed to be broken in because this was the first Volt I drove with only 7 miles on it. All the other Volts I test drove has a lot more miles on them. However the noise level never got any better. It appears to get louder the longer the car has been driven on a given trip. It is especially noticeable when doing 3 point turns or anytime you come to a complete stop (parking, stop lights etc.). It's really not something that would bother someone who drives the car on a short trip for a short period of time however it is really annoying when you drive it every day. I'm not new to regenerative braking as we have a Ford Escape Hybrid and I have test driven a lot of Volts and Leafs and none of them had brake pedal noises like my Volt does. Even the dealership was able to confirm that it is louder than any of the Volts they've had. The noise does exist on other Volts but in my opinion it is like 40-60 times louder on my car.

Timeline:
January 7th 2012: Had dealer check out excessive brake pedal noise. The dealer confirmed that it was louder than other Volts. I was told that they had to open a case with GM before they could work on it. Because I was limited on time I did not want to leave the car with them. I told them due to pending battery enhancements I would just bring it back and get everything fixed at once.

May 5th 2012 thru April 15th 2012: Dropped off my car so dealer could perform work. I asked to get all service bulletins fixed while it was in there but the priority was the brake pedal noise. Dealer had called me on Wednesday May 9th that they were waiting for battery lift and still didn't fix the brake pedal yet. I let my Volt advisor know what was going on. Friday May 11th I got a call that the car was ready. I asked if everything was done they said yes then paused and said except the brake pedal noise. I immediately called my Volt Advisor to explain that the brake Pedal Issue really bothers me and I want it fixed. He told me that he was going to contact the GM technical advisors and have them speak with the dealership and see if they can get that fixed while it's still at the dealer. I called the dealership on Monday to see if they were working on the pedal and they confirmed they were. Tuesday I got a call from the Dealership that the car was ready but they still didn't fix the pedal. They identified the issue but they were told it was normal for sound levels of the brake pedal to vary between cars. At this point I wanted my car back. I asked the service rep to provide me an estimate to get this issue resolved. I probably would have just paid to get the brake valve replaced if I could have picked it up and it be replaced.
 

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Old Habits Die Hard

Wow, that's a bummer. It's a shame that you're not able to experience the driving pleasure that's been almost universal for other owners.

But what's really disturbing is the classic GM response "Oh, that's normal" to anything that doesn't actually make a vehicle un-usable.

I hope this doesn't herald the end of GM's commitment to open communications about the Volt.

Jim Bell
2012 Volt
 

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I have a similar noise. I was told it is caused by the brake system hydraulic pump. Mine also seems much louder on my Volt than on other Volts I have test driven. I have had the dealer look at it twice, but they can only tell me that it's normal, even though they admit that other Volts don't seem to have the same issue. I'm still not happy about it, but it hasn't been a priority compared with the two other issues I have had (bad traction battery relay and no A/C refrigerant).
 

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I had an issue with brake noise also. I took it to the dealer 4 times before they fixed it. I got the "that's normal" thing too, which really ticked me off because I KNEW it wasn't normal. My brakes were making a creaking noise. I finally did a youtube video and sent it to my Volt Advisor. She forwarded it to the right people, who called my dealer...and now my problem has been solved. They replaced the pads and clips on my Volt, and the noise stopped.
 

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Discussion Starter · #5 ·
On my computer at home I can hear the noise on the video but I can't on the video at my work so I'm not sure how helpful that video will be.
 

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"I had an issue with brake noise also. I took it to the dealer 4 times before they fixed it. I got the "that's normal" thing too, which really ticked me off because I KNEW it wasn't normal. My brakes were making a creaking noise. I finally did a youtube video and sent it to my Volt Advisor. She forwarded it to the right people, who called my dealer...and now my problem has been solved. They replaced the pads and clips on my Volt, and the noise stopped. "

Is that what I hear? It sounds like crickets chirping as you both apply pressure to the brakes and release them. Its a little annoying, but not a big deal.

Can you send me the link to your youtube video?
 

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Discussion Starter · #7 ·
I did notice a difference on my work computer. It seems like the speakers filter out that particular sound. I'll try to get a better video.
 

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One thing this thread points out is how AWESOME it is that GM has the Volt Advisor team. It goes a long way toward helping get their dealer network in line... Another reason perhaps a Cadillac launch may have been a good choice. Dealers don't see this as a halo car (like a Corvette). They see it as an expensive Cruz. Chevy dealers just don't get how great this car is.
 

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Discussion Starter · #9 ·

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My 2012 has the exact same brake noise.
I refer to it as a "groan" or "growl" at the end of the pedal travel. The slower you press the pedal the longer it groans.
It is at the dealer now for the strut replacement and this issue.
They have had it for a day and so far this noise is stumping them and the GM Volt brake engineers my dealer contacted.

Did you ever get a cause and resolution so I can inform my dealer?
 

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The motor/pump noises I hear on the videos (commencing after a couple brake applies) would be considered normal for the Volt and assuming that is what you are focusing on. I hear a bit of pedal spring squack as well but that's something that would be present even when OFF(which you say isnt the case)

These noises are not really abnormal just different from other cars.
However If these pump/motor noises are louder than "typical" (compared against another Volt side by side) the dealer should looking for a potential reasons why the motor pump assembly or Electro-Hydraulic Brake Unit isnt as isolated as it should be (bad pump, BPMV mounting, brake lines touching frame/sheet metal etc)
Hopefully they find something
WOT
 

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The brake grinding is typical for glazed pads that occurs when they are not used extensively or after a car wash. It is the oscillation of the pads/rotors transition from static to dynamic friction and back. It is annoying, but it can be observed on all cars with automatic transmission or if the car is on a downhill and fighting the brakes.

I am more concerned with the brake pedal twitching. It was described as "the brake pump building pressure" and "normal". Ok, fine, why can't it build pressure and hold it without twitching the pedal? The twitching makes me want to release the brakes, which given many circumstances is not a good idea.
 

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The "groan" or "growl" that is occuring on my vehicle and the one in the youtube videos is occuring not only when the car is moving but when the car is in "Park" as well.

So it is not brake pad noise.
 

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I have had the dealer look at it twice, but they can only tell me that it's normal, even though they admit that other Volts don't seem to have the same issue.
Oh, those wacky people, with their tenuous grasp on logic.
If other Volts don't do it, then it is, by definition, NOT NORMAL!
 

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Half of the ICE cars I have owned made a hissing vacuum assist noise that was louder than the noise you are showing in the video. If it's indeed louder than other Volts it should be looked at. If the dealer is not giving you good service try another dealer.
 

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The other Volt on the dealers lot did not make any noise at all.
The "groan" or "growl" that is occuring on my vehicle and the one in the youtube videos is occuring not only when the car is moving but when the car is in "Park" as well.
ALL Volts make this noise when the hydraulic brakes are active and will also vibrate the pedal slightly that some people might feel.
This normal event may be more noticable under certain HYDRAULIC braking conditions.

It occurs whether the car is stationary or not, but typically MORE noticable when you are:
- stationary or at stop light/sign
- at very low speeds (since you wont be capable of regen braking and ALL braking is hydrualic)
- hard braking (such as in a panic stop where regen and hydraulic braking is "blended")

If you want to better hear the source of the noise (motor driven pump) or to compare it's noise levels, power up the car in service mode (hold power button for 5-6 seconds, FOB in car foot OFF brake) pop your hood and focus your ear on the area shown in the diagram below. (near master cylinder brake fluid reservoir) Then have someone step on the brake pedal a few times- you will hear the pump motor run. The pitch of the motor will change slightly depending on how hard the pedal is being depressed.

DON'T FORGET TO POWER DOWN THE CAR IMMEDIATELY AFTER AS YOU CAN DRAIN YOUR 12V BATTERY IN THIS POWER MODE!

HTH
WOT

 

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what year volt do you own?
does yours make this noise?
"ALL" volts DO NOT make this noise since the one on the dealer lot did not, additionally no other reply but mine says "Mine To".
The dealer as of yet has not discovered the source of the noise but they are comparing mine to the lot vehicle.
I would assume that they have done this in service mode.
 
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@ Hipo65,

Could you please send me a PM with your VIN and contact info? We can get into contact with your dealer and see if we can point them in the right direction.
 

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I've noticed this noise & vibration on my Volt but it's subtle and doesn't bother me as long as it's not indicative of a pending failure. I only hear/feel it at the very end of a stop and I figured that it was a transition from regen to hydraulic. It would be great if the Volt was always magically silent but, unfortunately, even though it is most of the time, it's still a very complex animal that makes some strange sounds occasionally. A re-engineer of the hydraulic pump/brake system may be needed to eliminate this completely.
 
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