antilock brakeing?

[Richard H.]

New Chevy Sonic, 3 months since I bought it, about 3k miles. When braking in slushy conditions front end bumps up and down. First couple times it did this there was a loud clunk and grinding noises. Sometimes while not braking, just driving on the street, the front passenger wheel sounded like it was rubbing on something. This noise also involved some clunking, but mostly just a squeel that faded down and then stopped after a few minutes. I heard that noise several times while not braking, just driving on city streets at less than 30 mph. After a few days it did not do it any more.

This is not just a little vibration in the steering wheel. Twice I have been startled into thinking I had lost control of the car. I took it back to the dealer after this braking issue had occurred several times. The dealer turned the rotors and said it was fixed. It was not. The next day it did it again when stopping at a stoplight in traffic. I really thought I had lost control of the car. When it did come to a stop, the brake pedal turned mushy and sunk halfway to the floor. I had the dealer look at it again, and a few minutes ago the service manager called and said what I am experiencing is normal ABS behavior. He said there is nothing wrong with the car.

I have driven several cars with ABS and never experienced anything like this before. If I had known this was "normal" behavior I certainly would never have bought the car. The car is now at the dealer and I have a loaner. Frankly I am afraid to drive the car, and I worry about my wife driving it. I bought the car for her to use, and I drive much less than she does. So what can I do? Thanks for your ideas.

 

[ThatTmoGuy]

Take it to a different dealer if you can,if you can't take it to midas for a free inspection and see what they say.

 

[lambertsonic]

Wow great first post !

 

[Richard H.]

Thanks. I'll keep checking.

 

[CyberGreyTURBOZ]

Auto or Manual?

Manual trans cars in my experience have always had a firmer and more responsive peddle. Sometimes they are very touchy. What kind of "Normal ABS" is the dealer referring to? Sounds like no pads to grab or something very wrong if you don't feel safe stopping. The only odd noise I have heard from my Sonic was when I grabbed the E-brake in the snow with stabilitrac still on. It slide for a moment then made a few noises like "WTF Is Going On!"

 

[firstorbit84]

maybe try pulling the ABS fuse and see if it still does it?

warning: you will not have ABS!


side note: the brakes are extremely sensitive in this car, but they also stop very well. it takes a lot of effort and would have to be an emergency situation for me to try to get my ABS to engage

 

[Swordsmith]

I found ABS very intrusive and felt it was in fact dangerous when I first used it on this car. It went on under very gentle slide conditions, and it went on suddenly and violently, pounding hard like a jackhammer under the front axle, and interfering with my steering. I was terrified, to be frank about it.

I've driven cars with ABS for many years, and never had anything like that happen, ABS generally feels like someone mounted a vibrator to the brake pedal, and you brake a little differently then you expect, but not seriously so. This was very very different.

Subsquently, though, the Sonic ABS calmed down, and I became more used to it. It still feels different, a slower harder rhythm compared to other cars, but not jolting and jerking the whole vehicle around.

Part of this may be the Traction Control system; I routinely click it off when starting the car now. But part may be that the system needed a few hard sliding stops to wear in, and has now reached it's operational state. If this is so, A) I think Chevy should include something in their line which forces the car to do that hard stop a few times before they sell it to us but B) I think every Sonic owner should know that the first snowy/icy day they can find, they should go out and do a few hard stops somewhere safe (you only have to go 10 mph or so, doesn't have to be something huge, you just have to tromp down on the pedal where you will induce a slide.

If you're still having the same response after doing this a few times though, and have tried TC off, then I'm guessing there's more of a problem, as I'm no longer having that issue.

 

[Chevrolet Customer Care]

If any one has any issues with their vehicle or the dealership, please PM us with your VIN#, name, situation, contact information, dealership, and mileage. Regards.

Matt,

GM Customer Service (Assisting Vanessa)

 

[Leverus]

Subsquently, though, the Sonic ABS calmed down, and I became more used to it. It still feels different, a slower harder rhythm compared to other cars, but not jolting and jerking the whole vehicle around.

Part of this may be the Traction Control system; I routinely click it off when starting the car now. But part may be that the system needed a few hard sliding stops to wear in, and has now reached it's operational state.

I thought I was just crazy until you posted this. I can't be sure if it's just me getting used to the system, but it doesn't feel nearly as severe as it did at first for me as well. But what part of the ABS system would "break in"? My bet is still on having learned how the car likes to be driven in bad conditions.

 

[ThatTmoGuy]

I said f*ck abs and traction control and pulled out the fuse.