rmakela
Posts: 2
Joined: Thu Oct 06, 2011 7:24 am
Delivery Date: 06 Oct 2011
Leaf Number: 4823

Grabby Brakes?

Thu Oct 06, 2011 7:38 am

I saw this topic mentioned a few months back - but no real resolution. I have about 3000 miles on my Leaf. I've recently started experiencing a grabbing of the brakes/regen, especially when I'm going down a long hill or coming to a rolling stop. It's really inconsistent and makes it impossible to come to a smooth stop. I thought it was just me, but it seems to have gotten worse. It happens whether I am charged to 80 or 100%. Anyone else experienced this condition? I'm not willing to let this one go as a "feature" of regen - it seems borderline safety issue to me, especially when you stop much quicker than expected with traffic behind you. Any ideas?

Ray

lincomatic
Posts: 312
Joined: Fri Jun 10, 2011 10:01 am
Delivery Date: 06 Apr 2011
Leaf Number: 3819

Re: Grabby Brakes?

Thu Oct 06, 2011 8:18 am

If it happens w/ 100% SOC, then it's not a regen issue. And if it shows up after 3000 miles, then something has changed. Take it in to the dealer and have them check it out.

cdrews
Posts: 8
Joined: Sat Apr 23, 2011 8:09 am
Delivery Date: 21 Apr 2011

Re: Grabby Brakes?

Thu Oct 06, 2011 8:27 am

I was just thinking about posting exactly the same thing :). I have the exact same problem.

Has anyone brought their leaf back to the dealer to examine the problem?

-= Clemens

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abasile
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Re: Grabby Brakes?

Thu Oct 06, 2011 8:34 am

I've experienced the same thing occasionally. The brakes act more grabby than usual. However, I'm not going to bother taking the car to the dealership for what is at worst a minor annoyance. I've never thought of this as a safety issue because I've found it easy to respond by reducing pressure on the brake pedal.
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mwalsh
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Re: Grabby Brakes?

Thu Oct 06, 2011 8:53 am

abasile wrote:I've never thought of this as a safety issue because I've found it easy to respond by reducing pressure on the brake pedal.


Except in some instances that doesn't work. The specific one I'm thinking of....you're sitting stopped in stop-and-go traffic when the cars in front of you start to inch forward. So you let up off the brake pedal, allowing your car to creep forward. But then the traffic ahead stops again, so you need to reapply your brakes. Sometimes when you do this the brakes grab with inappropriate force, causing the car to come to a very sudden stop, even with very minor force on the brake pedal.
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TomT
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Leaf Number: 000360
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Re: Grabby Brakes?

Thu Oct 06, 2011 9:00 am

I've experienced the same phenomena on occasion and have learned to live with it... It seems like a bug in the Brake Assist algorithm to me...

abasile wrote:I've experienced the same thing occasionally. The brakes act more grabby than usual. However, I'm not going to bother taking the car to the dealership for what is at worst a minor annoyance. I've never thought of this as a safety issue because I've found it easy to respond by reducing pressure on the brake pedal.
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davewill
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Re: Grabby Brakes?

Thu Oct 06, 2011 10:08 am

Yeah, it happens on occasion when I'm stopped, or nearly stopped, and trying roll forward slowly. You can't apply pressure lightly enough to do anything but lurch to a stop. The only way to clear the problem is to release the brake completely. It's been an annoyance, but not a big enough one to complain about.
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DarkStar
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Leaf Number: 568
Location: Hillsboro, Oregon, USA
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Re: Grabby Brakes?

Thu Oct 06, 2011 10:16 am

I always thought this occurred because the pump hasn't recovered its pressure yet. Either way, this happens to me too, only at very low speeds, while creeping. Same as davewill.
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Christopher
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Re: Grabby Brakes?

Thu Oct 06, 2011 10:29 am

I've actually experienced the opposite effect. On several different occasions at low speeds, many weeks apart, I've been surprised to suddenly find the brakes not responding normally and I'll need to press much harder to get the intended effect. It's very disconcerting. I can still stop but it takes much more effort and it's very hard to brake smoothly. And then a few minutes later, things are back to normal. (And no, it's not wet conditions.)

Now that I think about it, perhaps this is the same effect others are describing as very grabby. They're certainly very grabby when I push harder to compensate -- it's just that I first notice how they don't respond properly with normal pressure on the pedal.

There's no common situation this happens other than I think it's only ever happened soon after starting the car from being parked somewhere briefly -- never while I've been driving a while or parked for a long while.

FairwoodRed
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Re: Grabby Brakes?

Thu Oct 06, 2011 10:58 am

Wow. Talk about great timing. I signed in this morning (after a few weeks off) just to research this problem. I've got 5500 miles on and I fight the grabby breaks a lot now. Particularly in slow rolling freeway traffic. It's getting to the point that I am worrying about getting rear ended. I plan to bring it up at my service visit in 2 months, or sooner if I find myself at the dealer. Thanks for bringing it up Christopher!

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