mikeyagi
Posts: 1
Joined: Wed Mar 21, 2018 6:21 pm
Delivery Date: 11 Mar 2018

2018 Leaf spongy brake pedal?

Sun Jun 03, 2018 3:49 pm

The brake pedal on my US market 2018 Leaf feels really “spongey” and soft when fully depressed. It doesn’t seem to affect the braking. But compared to every other car I’ve owned, it never feels solid. If I’m sitting at a light with my foot on the brake, I can push it in and out a good inch of squishy play.

I usually drive in E-pedal mode so I’ve only just started to notice this. But it kind of makes me nervous. Maybe it’s because the last car was a BMW 3 which had superb brakes. Or maybe I don’t know how regen brakes are supposed to feel.

Does anyone else have this experience?

Oils4AsphaultOnly
Gold Member
Posts: 405
Joined: Sat Oct 10, 2015 4:09 pm
Delivery Date: 20 Nov 2016
Leaf Number: 313890
Location: Arcadia, CA

Re: 2018 Leaf spongy brake pedal?

Mon Jun 04, 2018 11:36 am

mikeyagi wrote:The brake pedal on my US market 2018 Leaf feels really “spongey” and soft when fully depressed. It doesn’t seem to affect the braking. But compared to every other car I’ve owned, it never feels solid. If I’m sitting at a light with my foot on the brake, I can push it in and out a good inch of squishy play.

I usually drive in E-pedal mode so I’ve only just started to notice this. But it kind of makes me nervous. Maybe it’s because the last car was a BMW 3 which had superb brakes. Or maybe I don’t know how regen brakes are supposed to feel.

Does anyone else have this experience?


Hard to tell from your description if it's truly "squishy" or just soft/gentle? Other cars might feel more grabby, but I've always considered the leaf brakes as more progressive (like Honda's Odyssey). Press lightly for slight braking, and deeper for stronger braking. Are you getting that?

Maybe you should carry out some successive hard brake tests just to check for brake fade (not enough vacuum pressure from your brake booster)?
:: Model 3 LR :: acquired 9 May '18
:: Leaf S30 :: build date: Sep '16 :: purchased: Nov '16
Date - Miles / GIDs:
May '17 - 7300 mi / 363
Feb '18 - 20.5k mi / 333
... awaiting firmware update

GerryAZ
Gold Member
Posts: 1727
Joined: Mon Nov 22, 2010 6:47 pm
Delivery Date: 12 Jun 2011
Location: Phoenix, AZ

Re: 2018 Leaf spongy brake pedal?

Tue Jun 05, 2018 7:47 pm

If the brake pads are not fully seated against the rotors, the pedal will feel soft/spongy. In my case, both 2011 and 2015 took quite a while for the ceramic pads to wear in to get full contact against the rotors. The pedal (in each case) was much firmer after the pads were fully seated.
Gerry
Silver LEAF 2011 SL rear ended (totaled) by in-attentive driver 1/4/2015 at 50,422 miles
Silver LEAF 2015 SL purchased 2/7/2015

phototrek
Posts: 2
Joined: Fri May 04, 2018 10:10 pm
Delivery Date: 05 May 2018

Re: 2018 Leaf spongy brake pedal?

Wed Jun 13, 2018 5:05 pm

The problem seems to be related to e-pedal mode only, and pertaining to brake blending. This is by far the worst EV / PHEV that I have ever driven in that regard, and that's been many.

The problem is that the brake pedal position is mapped to an overall braking force. On other words, if you completely lift your foot off the gas in e-pedal, you are already decelerating (quite heavily at that), and now you gently press the brake, which tells the computer that you want to gently decelerate - thus commanding a decrease in overall braking power. Similarly, if you're on the brake and say are doing a California Stop, i.e. easing off the brake before coming to a complete stop, you will feel that the car actually brakes more as you ease off the brake until you get your foot on the gas.

I work in the EV industry so I find this lapse of testing to be simply baffling, as any Ford/Mercedes/Tesla/VW/Chrysler/BMW/Audi EV/PHEV that I've ever driven had completely smooth brake blending (with regen mode), but somehow perplexingly the company that's been at it the longest has such a bug (that probably will never be fixed, at least for existing cars). Baffling. Causes a bad experience for passengers because there's simply no way to do a smooth roll-stop, and is confusing for the driver because one and the same brake position has different retardation as result.

Leaf15
Posts: 28
Joined: Sat Jun 09, 2018 6:51 am
Delivery Date: 09 Jun 2018

Re: 2018 Leaf spongy brake pedal?

Sun Jul 01, 2018 6:22 am

Although I liked e-pedal idea, it has a few quirks that make it look like it has glitches in accelerator to brake pedal and reverse transitions. The human-to-vehicle interface in this mode is a bit awkward during those transitions. Perhaps easily accessible strong regen momentary button is all that was needed (like in Bolt).
Leaf 2015 SV CPO

phototrek
Posts: 2
Joined: Fri May 04, 2018 10:10 pm
Delivery Date: 05 May 2018

Re: 2018 Leaf spongy brake pedal?

Sun Jul 01, 2018 7:26 am

... or a proper software fix to brake blending so that it works like in Audi, BMW, Mercedes, Tesla, Toyota, VW, or Kia cars :)

Heck even the Bolt has the equivalent of e-pedal (B mode), and brake blending works correctly there.

User avatar
Nubo
Posts: 4805
Joined: Fri May 28, 2010 11:01 am
Delivery Date: 31 Oct 2014
Location: Vallejo, CA

Re: 2018 Leaf spongy brake pedal?

Sun Jul 01, 2018 11:26 am

mikeyagi wrote:The brake pedal on my US market 2018 Leaf feels really “spongey” and soft when fully depressed. It doesn’t seem to affect the braking. But compared to every other car I’ve owned, it never feels solid. If I’m sitting at a light with my foot on the brake, I can push it in and out a good inch of squishy play.

I usually drive in E-pedal mode so I’ve only just started to notice this. But it kind of makes me nervous. Maybe it’s because the last car was a BMW 3 which had superb brakes. Or maybe I don’t know how regen brakes are supposed to feel.

Does anyone else have this experience?



Sounds like my 2012 and 2015. One the pedal reaches a certain maximum pressure, you can just "push through" to the floor without any further increase. I just figured it must be some kind of compensating valves related to the ABS. I've always found the braking on these cars to be quite good with the exception of some low-speed grabby-ness that arises periodically and can be removed by "calibrating" the system (hold pedal all the way to the floor while stopped, and hold for at least 30 seconds.
I noticed you're still working with polymers.

kennethbokor
Gold Member
Posts: 76
Joined: Mon Mar 14, 2016 12:35 pm
Delivery Date: 30 May 2018
Location: Caledon, ON Canada
Contact: Twitter

Re: 2018 Leaf spongy brake pedal?

Wed Jul 04, 2018 8:14 am

Brakes are "brake by wire" so it's a different feel then normal hydraulics. There is nothing wrong with them.
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New Leaf Owner: Just ordered Feb 24 2018, 2018 Leaf SL in Jade Frost. Expected ETA by May 30 2018.

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