Occassional but SEVERE grinding when engaging brakes

[dermo]

For some reason my Sonic, when going down steep hills, the brakes will grind horrifically. I can feel it in the pedal. The most prominent issue was right after it got done snowing when I was going down my snowy driveway in the car. I mean, I know that's not good. I'm guessing its the ABS. I think my rotors might be warped? I don't have time to CONSTANTLY take it back to the dealership .

 

[Eric Smit]

abs dude. not even a worry.


-Eric Smit

 

[Beastlick]

You are probably feeling the ABS kick in. They kick in VERY early in the sonic!
To test this go into a snow covered parking lot, speed up and press hard on your brakes.... If you get the same feeling, its nothing to be worried about, just the touchy ABS.

 

[Beastlick]

abs dude. not even a worry.


-Eric Smit

Hidden bolt ninja and quick post ninja! I need to type less....

 

[Eric Smit]

it's a gift.


-Eric Smit

 

[Swordsmith]

And yes they do sound and feel like you're grinding the road into gravel. Very disconcerting even if you've had ABS kick in in other cars, this is nothing like that.

In another thread, it's been suggested that if you take off TC that the ABS will be a lot less aggressive, I haven't tested that out but it does seem to me that that was the case, the two trips I've taken in snow, one with TC and one without, the latter ABS was a lot less scary and intrusive.

 

[Beastlick]

on a plus note, I do find myself slowing down way before I need to, just incase the ABS decides i'm being too rough with her and thinks the better alternative to locking the brakes would be to slam into another vehicle/person.

I really wish my tune could pull the reigns back on these a little bit, but I understand "the safety" issues.

 

[Swordsmith]

By which you mean Vince et al aren't prepared for the lawsuit your heirs would unleash if they found out they helped you tamper with your ABS?

 

[Chevrolet Customer Care]

For some reason my Sonic, when going down steep hills, the brakes will grind horrifically. I can feel it in the pedal. The most prominent issue was right after it got done snowing when I was going down my snowy driveway in the car. I mean, I know that's not good. I'm guessing its the ABS. I think my rotors might be warped? I don't have time to CONSTANTLY take it back to the dealership .

Dermo, After checking the Sonic's Owner's Manual pg. 9-28, Driving and Operating section, it says the following about ABS:

Using ABS Do not pump the brakes.
Just hold the brake pedal down firmly and let
ABS work. You might hear the ABS
pump or motor operating and feel
the brake pedal pulsate, but this is normal.




Vanessa
GM Customer Service

 

[Swordsmith]

Pulsate is not a very good word for what ABS feels like with TC on. More like "you may feel an elephant is kicking you in the foot while you slide over a rutted road filled with jagged gravel"

Pulsate is what ABS feels like on other cars. Sort of like someone is using a Shower Massage on your foot, a little odd but not odd enough to be disconcerting.

Even with TC off, it's more a case of "you may feel like a Dalmation is kicking you in the foot while you slide over a gravel road"

 

[SonicBoy24]

Yea that sounds like ABS. My driveway is completely flat, and even when there is light snow on it my ABS kicks in when I slow down at the end. I don't get any faster than 10mph in my driveway...

 

[2012LTZ]

Me too, and I don't think I can just write it off as abs because it's just plain noisy. There is lots of driveline noise in my car and it's not just the brakes. I read before I bought my car that the sonic is road noisy and have just been chalking it up to that. Another issue that made me question things is that the car seemed hard to get whoa'd down sometimes. As if when the engine downshifts it gets more torque and a burst of power that makes it seems like the brakes aren't working the way they should. (I REALLY MISS my straight drive - which is a term in the south for standard transmission ). All of the braking weirdness goes away to some extent when I put the stock map back in.