ncerna
Posts: 76
Joined: Sat Jun 17, 2017 4:25 pm

Questionable brakes system...

Sun Jul 09, 2017 7:50 pm

Anyone else experience brake issues with their car?

I have noticed that my Spark behaves inconsistently when stopping suddenly.(Not at very high speeds)
There are times when I press the brakes and the car feels like it is sliding more than stopping.
I am not a very fast driver. I always leave plenty of space in front of me while driving.

But I still have to be very careful when braking. Sometimes the car stops normally.
At other times it seems to take forever to come to a complete stop.
Often times it feels like the car is sliding forward. Or I'll hear the tires chirp. It's a little embarrassing.

When I have other passengers in the car, I have to be even more careful. Then the brakes seem even less efficient.
This has caused me to wonder just how safe my car is to drive.
I know that in case of an emergency, or if the car in front of me were to stop suddenly, there is a good chance I would get into an accident.

I would be hesitant to lend me car to anyone, for fear they may get into an accident.
Is this normal for the Sparks??

JPL
Posts: 117
Joined: Sun Jul 09, 2017 11:42 pm
Location: Vancouver, BC

Re: Questionable brakes system...

Mon Jul 10, 2017 12:01 am

Are you driving on D or L?
2016 Spark EV w/CCS
Front Speakers: Alpine 4" (SPS410)
Back Speakers: Alpine 5X7" (SPS517) w 3D print adapters

17 " Rims
F: Michelin Pilot Sport A/S3 205/40R17
B: Hankook 205/45R17

2020 Kia E-Soul

2000 Honda Insight MT

PhilPen
Posts: 72
Joined: Mon Oct 31, 2016 9:54 am
Location: Hamden, CT

Re: Questionable brakes system...

Mon Jul 10, 2017 5:22 am

What I think you could be experiencing is reduced regenerative breaking which can occur under very special circumstances (when the battery is essentially completely full and is of no safety concern in my opinion). Under these circumstances a little more brake pedal travel is required to get the desired braking effect. I experience this fairly often because I live half way up a long steep hill. If the car is completely fully charged and I head down the hill there is noticeably less braking for the very initial portion of brake pedal travel than if I did the same trip with the battery not fully charged because there's nowhere to dump the energy and it seems under such circumstances that the mechanical brakes provide the woah power and thus a little the further brake travel is required for activation. This effect is also noticed in 'L' as you just coast on like you are in 'D' under such circumstances. If I head on a route taking me up the hill with the freshly fully charged battery the braking behaves normally because I have made 'space' in the battery before the first braking event, and even when I head down the hill the greater brake travel is only required in my case for the first traffic light at the bottom of the hill, as the next light occurs after a sufficient period of horizontal power consuming travel. I would expect if a journey starting with a fully charged battery initially involved a lot of long down hill sections it could be experienced even more frequently.
2015 Spark EV 2LT electric blue with DCFC
2016 Spark EV 2LT salsa red with DCFC

ncerna
Posts: 76
Joined: Sat Jun 17, 2017 4:25 pm

Re: Questionable brakes system...

Mon Jul 10, 2017 7:32 am

It happens in either the 'D' or 'L' mode. I tested both to see if it made a difference in the feel of the car.
Using the 'L' mode does help a little. It helps in the initial slowing of the car.
However, the part where it feels unsure is when I have to come to a complete stop.
Stopping power is inconsistent. Or rather, it is consistently poor.
(And when I have other passengers in the car, it feels outright dangerous)

I dropped my car off at a mechanic who specializes in suspension and brakes. I asked them to inspect the car and do a wheel alignment if necessary.
If they find any issues I plan to take it back to the Chevy dealer and ask them to fix it.

I'm hoping it won't be anything serious.

NORTON
Posts: 1273
Joined: Fri May 01, 2015 5:52 am
Location: KC,MO

Re: Questionable brakes system...

Mon Jul 10, 2017 10:08 am

You could test the friction brakes alone by shifting to N.
Then it should feel like a normal Spark, with normal power assisted brakes.
You, the local shop and the dealership should all agree that it does brake in N like a normal Spark.
Then, if the problem continues it may be some regen/friction brake interface problem.

I recommend doing some hard braking in N just to get the pads and discs 'bedded in' together. These cars rarely use the friction brakes hard....
Used '14 2LT w/ DCFC. +76 K miles.
Mostly free charging! Only one LONG visit to the shop....
GM needs Modern Troubleshooting tools for Modern EV's.
3 step Trouble Tree, 2nd guess not covered by warranty and cost $800. 3rd guess fixed the problem.

ncerna
Posts: 76
Joined: Sat Jun 17, 2017 4:25 pm

Re: Questionable brakes system...

Mon Jul 10, 2017 3:34 pm

A couple days ago I did some really hard braking at low speeds, just to test the brakes.
When pressing really hard on the brake pedal, I felt an ugly feeling. Like the car bottomed out.
But maybe it was just the ABS. I used to own a Chevy Sonic, and I noticed it would do the same thing when slamming on the brakes.

NORTON
Posts: 1273
Joined: Fri May 01, 2015 5:52 am
Location: KC,MO

Re: Questionable brakes system...

Tue Jul 11, 2017 7:06 am

ncerna wrote:...But maybe it was just the ABS. ...
Yes, ABS.
So many drivers don't have a clue what a panic stop should be like. I suspect so many rear-enders happen because of someone not braking as hard as the car is capable of.
They never practice, there is no driver training anymore, blah blah blah, everybody is expected to just get by....

And, as I said, the Spark EV brakes can go for months and never get hot, or even warm, from use.
Used '14 2LT w/ DCFC. +76 K miles.
Mostly free charging! Only one LONG visit to the shop....
GM needs Modern Troubleshooting tools for Modern EV's.
3 step Trouble Tree, 2nd guess not covered by warranty and cost $800. 3rd guess fixed the problem.

ncerna
Posts: 76
Joined: Sat Jun 17, 2017 4:25 pm

Re: Questionable brakes system...

Tue Jul 11, 2017 11:55 am

That might be why the car display has the green ball. To discourage drivers from either quickly accelerating, or braking hard.

nikwax
Posts: 567
Joined: Sun Apr 26, 2015 3:27 pm
Location: Portland, Oregon

Re: Questionable brakes system...

Tue Jul 11, 2017 7:21 pm

another factor could be the dreadful OEM tires, they have very little grip. You mention chirping, so I though of tires.
2015 Spark EV 1LT DCFC
BF Goodrich g-Force Super Sport A/S
ClipperCreek EVSE

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