GroundLoop
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Brakes "mutate" to become grabby in stop & go traffic?

I was stuck in slow-moving traffic going downhill, gradually releasing and applying the brakes to creep along, one car length at a time. (No accelerator at all.)

Over about 10 minutes, the brakes took on a very "binary" feel -- they were either grabbing hard, or fully released, and I couldn't gently apply them. They became very "grippy" and abrupt. I tried releasing completely, but didn't get any improvement.

I put the car in park for 10 seconds or so, and then Drive, and everything was fine.

Anyone else experience something like this?

Just to restate -- at no time did I feel "unsafe", I just had very little analog control of the brakes. With cars close behind, I didn't want to experiment further.
91040
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Re: Brakes "mutate" to become grabby in stop & go traffic?

This has been mentioned in other threads. It has happened to me on a couple of occasions too. The consensus seems to be that it has to do with the anti-lock brake controller. So far it has been annoying but not dangerous.
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highcountryrider
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Re: Brakes "mutate" to become grabby in stop & go traffic?

I have noticed times when the brakes seemed a bit grabby; I'll have to try putting it
in PARK next time and see what happens.
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DaveL
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Re: Brakes "mutate" to become grabby in stop & go traffic?

91040 wrote:... The consensus seems to be that it has to do with the anti-lock brake controller. So far it has been annoying but not dangerous.
Interesting. I've noticed the brakes becoming "grabby" as well, but never thought about it being in the anti-lock brake controller.

However, that would be consistent with what happened to me the other day: I had to stomp on the brakes to avoid an accident when a pickup cut me off on a 4 lane / 30 mph road. The ABS kicked in, but didn't feel like any other brake system I've felt in our other cars. Instead of the break peddle pushing back in a rhythmic pattern (like someone hitting the back of the peddle with a hammer), it felt more like a vibration.

The disconcerting part had to do with what happened next as I let up on the peddle before coming to a complete stop: the ABS system didn't disengage until I took my foot completely off the peddle. By then the car had come to a complete stop and I was checking the rear view mirror to see if someone was going to rear-end me. Luckily there was no one close behind me, so I pressed on the gas and the car took off like nothing had happened.

The next time I find myself alone on a street (and can do so safely) I plan on stomping on the break again to see if I can replicate the situation. Meanwhile I'll try putting the car into "Park" the next time the brakes feel "grabby" and see if that makes a difference.
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91040
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Re: Brakes "mutate" to become grabby in stop & go traffic?

See these threads.

Grabby brakes-
http://www.mynissanleaf.com/viewtopic.php?f=8&t=6086" onclick="window.open(this.href);return false;
http://www.mynissanleaf.com/viewtopic.p ... 16&start=0" onclick="window.open(this.href);return false;

Braking after release of brake pedal- http://www.mynissanleaf.com/viewtopic.php?f=30&t=5888" onclick="window.open(this.href);return false;

Also the wiki has some info- http://www.mynissanleaf.com/wiki/index. ... rakes,_ABS" onclick="window.open(this.href);return false;
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TomT
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Re: Brakes "mutate" to become grabby in stop & go traffic?

Yep, they all seem to do that. It is most obvious (and annoying) when creeping along in very slow traffic and using the brakes to modulate your speed without taking your foot all the way off the pedal. The digital effect becomes more and more severe as you slightly apply and them remove pressure from the brakes while moving slowly. Taking your foot all the way off the pedal seems to reset the system and then the cycle starts over again and become more severe as you use them without fully taking your foot off and releasing them. I particularly noticed it the other day when I had to go a couple of miles in traffic that was only moving at best a few miles an hour - never fast enough, for the most part, to allow the brakes to be fully released. To me, it felt more like Brake Assist getting confused than the ABS. Perhaps the software algorithm is not quite what it should be...
GroundLoop wrote:I was stuck in slow-moving traffic going downhill, gradually releasing and applying the brakes to creep along, one car length at a time. (No accelerator at all.)
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TEG
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Re: Brakes "mutate" to become grabby in stop & go traffic?

Yes, I had too had been commenting about that behavior a while back.
I concluded it might be part of the "brake assist" feature.
I gather there is one panic stop scenario where they decided it is safer if the car "takes over" and brakes for you to complete the stop. Unfortunately it seems a little touchy and does that even for low speed minor stop and go incidents.

I bet Nissan will adjust this behavior in some future rev of the car (or firmware update). It is just a little too annoying and intrusive at times.
LEAFfan
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Re: Brakes "mutate" to become grabby in stop & go traffic?

GroundLoop wrote:I was stuck in slow-moving traffic going downhill, gradually releasing and applying the brakes to creep along, one car length at a time. (No accelerator at all.)
Is there a reason why you didn't use ECO so you wouldn't have to use your brakes so much? Even going down the mountains, I always use ECO and rarely need to use my brakes.
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planet4ever
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Re: Brakes "mutate" to become grabby in stop & go traffic?

LEAFfan wrote:
GroundLoop wrote:I was stuck in slow-moving traffic going downhill, gradually releasing and applying the brakes to creep along, one car length at a time. (No accelerator at all.)
Is there a reason why you didn't use ECO so you wouldn't have to use your brakes so much? Even going down the mountains, I always use ECO and rarely need to use my brakes.
I don't think ECO will help if you are creeping along. At least I can't seem to get any regen at all at very low speeds.

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garygid
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Re: Brakes "mutate" to become grabby in stop & go traffic?

Are these "annoying" braking characteristics being reported to Nissan (877-664-2738)?

To help Nissan become aware and improve the LEAF, we should be reporting these "unexpected" vehicle control "problems".
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