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Discussion Starter · #1 ·
I stumbled onto something today that frightened me for a split second. I started the car, but shifted a little sooner than normal to R, and the car started moving even though I had my foot on the brake. A split second later the brake petal loosened and I could push it farther and the car stopped, but it was unnerving to move a foot or so when I didn't intend to. Lesson learned, take your time between starting and shifting to back up. Luckily nobody was behind me in this parking lot.

Has anybody else experienced this?
 

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Hmm... I do what you describe every morning, and I suspect others do as well. Can you reproduce it? If not, it may have been a glitch. (This isn't meant to be an apology for glitches.)
 

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You need to be a bit more patient before slamming the car into reverse. It does take a few seconds for ANY power brake system to build up pressure. Conventional cars will do it too if you don't give the power brake system time to normalize. The brakes will ALWAYS work... It just requires more foot pressure to bake without power assist. You need to wait for power assist to help you brake... Otherwise you have normal brakes without power assist for a few seconds.
 

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Hi all
I have never had this happen but I always keep my foot on the brake but I don't do anything untill the car finishes boot up and says ready in the little car icon.

Thanks
Don
 

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Mine does that too. It can be a bit unsettling, but just 1 second of waiting to shift doesn't hurt me.
 

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You need to be a bit more patient before slamming the car into reverse. It does take a few seconds for ANY power brake system to build up pressure. Conventional cars will do it too if you don't give the power brake system time to normalize. The brakes will ALWAYS work... It just requires more foot pressure to bake without power assist. You need to wait for power assist to help you brake... Otherwise you have normal brakes without power assist for a few seconds.
That's ALMOST correct. On the Volt, only the front axle brakes work from the master cylinder without the power assist enabled. That might make a difference on a steep slope and/or slippery conditions.
 

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I always wait for all (startup) red lights to go off before I switch my gear to Drive or Low gear.
 

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That's ALMOST correct. On the Volt, only the front axle brakes work from the master cylinder without the power assist enabled. That might make a difference on a steep slope and/or slippery conditions.
Huh?!? Where did you learn this from? I'm under the impression that the Volt has a typical dual master cylinder system, with the right front and left rear on one and the left front and right rear on the other. I'm not sure any other approach is legal these days, actually.
 

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Hmm... I do what you describe every morning, and I suspect others do as well. Can you reproduce it? If not, it may have been a glitch. (This isn't meant to be an apology for glitches.)
What's funny I still employ a technique I was taught DECADES ago by my father. When I first start ANY car I let it "idle" for at least 5 seconds or so while I scan the gauges and allow the car to "wake up". Those few seconds aren't much but there were many instances where I had a problem and it took a few seconds for the car to identify and register the problem.

So I can say I have never experienced what you describe on either of my two Volt's I'm not surprised the power brake booster needs a second or two to wake up. Unless the car throws codes or the problem continues to get worse I would suggest giving the car a second or two before blasting off on any journey.

Good luck.
 

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Huh?!? Where did you learn this from? I'm under the impression that the Volt has a typical dual master cylinder system, with the right front and left rear on one and the left front and right rear on the other. I'm not sure any other approach is legal these days, actually.
Clearly described in the service manual. I'd post a copy here but I've been told before not to do that.
 

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Has anybody else experienced this?
All the time. It's normal behavior, though I agree it is a concern the first time you feel it. I usually try to always make use of my parking brake anyway, to minimize wear on a vehicle's parking pins and for added safety. Having that on removes any concern.
 

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All the time. It's normal behavior, though I agree it is a concern the first time you feel it. I usually try to always make use of my parking brake anyway, to minimize wear on a vehicle's parking pins and for added safety. Having that on removes any concern.
I've never noticed it in over 3 years. I do use the parking brake religiously though. It seems particularly noticeable in the Volt how it bangs on the parking pawl if you take your foot off the service brake with the car in Park on the slightest incline. Every time I forget I want to kick myself.
 

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I remember a post awhile back complaining about the excess time it takes for the Volt to initialize. I filed that away with the complaint about no glovebox light but then I can advise that pushing the start button and THEN attaching your seatbelt, the READY icon wins every time.

John
 

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I stumbled onto s.... I started the car, but shifted a little sooner than normal to R, and the car started moving even though I had my foot on the brake. A split second later the brake petal loosened ...
Has anybody else experienced this?
the brakes do work, but it takes a few seconds for the boost to build up, just your foot on the brake pedal only actuates regenerative braking anyway, That said, I think the owners manual recommends using the parking brake when Parked, I always do and recommend it to others.
 

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Discussion Starter · #15 ·
All the time. It's normal behavior, though I agree it is a concern the first time you feel it. I usually try to always make use of my parking brake anyway, to minimize wear on a vehicle's parking pins and for added safety. Having that on removes any concern.
Although every time I use the parking brake I get other strange feelings when I try to drive, the car pushes against the brake causing the rear to rise, then the parking brake releases. I assumed that was normal, but a bit unnerving if it decides to not work one time.
 

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Although every time I use the parking brake I get other strange feelings when I try to drive, the car pushes against the brake causing the rear to rise, then the parking brake releases. I assumed that was normal, but a bit unnerving if it decides to not work one time.
you are supposed to step on the brake fully before releasing the parking brake, the car tells you this if you try to release it on the instrument panel. yes, if you step on the accelerator pedal in reverse hard enough, it will release the brake, and will rise up first ....
 

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Although every time I use the parking brake I get other strange feelings when I try to drive, the car pushes against the brake causing the rear to rise, then the parking brake releases. I assumed that was normal, but a bit unnerving if it decides to not work one time.
You do realize you can manually disengage the parking brake by pushing the same switch you engaged it with don't you?

And you don't have to give it a lot of gas if you want it to automatically disengage. Just the slightest hair of pressure on the throttle for a second or two will trigger the auto disengagement if you are too lazy to manually switch it off.
 

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Curious how fast you got it into reverse. My memory says that GM has the ABS controller do a self test during it's startup procedure, and actuates the ABS pistons. If you encountered this, it would feel like it weren't stopping as quickly. Not 100% sure the Volt does this, but most GMs I've had in the past did. In my '98 Buick it was noticeable, in my '05 GMC it was less noticeable, but there if I got to it quick enough. I have slowed down my 'startup to reverse' sequence a bit in the Volt.
 

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Today I parked on a very slight incline. Put the Volt in Park, turned the car off, and before I could put on the parking brake I felt the power to the brakes reduce and had to press the brake peddle harder. Being in Park it was no worry. I just put on the parking brake and went about my business. Then I remembered this thread and thought I would pass it along. For me, no big issue.
 
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