td11pump

Hello to all!
I have a 2006 Cobalt LS Sedan. The car runs great! Ive had the whole front end replaced to find the "cluncking noise" Chevy fixed everything and the car rides and SOUNDS great!

Heres the problem. I replaced the brake Pads and rotors at 41500 miles b/c the old pads were looking thin and old rotors b/c they were looking worn.
I put the new pads and rotors on and bolted everything back together to factory tourque specs and gently drove the car, at slight brake pedal pressure I start to get a pulse/vibration. (30mph) At medium brake pedal pressure I get a big vibration (30mph). When I give the brake pedal full pressure the car has NO vibration or pules and slows down very quickly!
I use Raybestos Ceramic brake pads and Wagner Brake rotors on other cars and trucks that I've owned and have never had this problem. This is vexing the **** out of me!

Can anyone help with this problem and if you can what did you do to cure it? Thanks!

D4u2s0t

well brakes typically take a few hundred miles to wear in, and you should be going very easy on them untill they do. i would do the basics, make sure everything is installed properly, make sure the rotors aren't warped, (possible you were shipped a bad rotor) and go from there. the brakes are working fine, so that's not an issue. how long have they been on for?

mikejoness61

wow dude i have the same problem and its bothering the **** out of me...the techs at my work said i was supposed to change the shoes in the back too?

on the drums that is

i know it has to be the drums cause i can here this sqeaking noise when i'm coming to a stop as well

scribbles

Ceramic pads? Did you break them in?

D4u2s0t

brakes will squeel for a while also. that's normal.

mikejoness61

its not the rotors though its the drums i replaced my pads and rotors at like 14k and i'm at 19k now and it still does this ****...its def the drums

td11pump

D4u2s0t, the new brakes are on the car now for about 800 miles and it still does it. I was very gentile with the new pads and rotors, as I've been changing brakes for the past 31 years on all different cars and trucks (not a rookie to this)
Before I even put the rotors on They were measured for runout and warpage (I've also had bad "new" rotors) and they were streight and ballanced.
Thats why I asked this question with the brakes and what has anyone done to cure it.

Again rotors streight and balanced before they were put on and new brake pads. Why the vibration/pulse?

"its not the rotors though its the drums i replaced my pads and rotors at like 14k and i'm at 19k now and it still does this ****...its def the drums".

I checked the rear shoes and they have plenty of life left. If I change the drums the vibration will stop? The drums look good as well.

scribbles

http://brakingnews.r1concepts.com/20...6-104-105.html

A good read with a possible answer.

td11pump

Thanks Scribbles.
I've been using Raybestos for quite a few years now. Maybe I'll try something different.
But this really has me stumpped. Thanks.

Mr_Slobalt

iTrader: (1)

Did you clean the hubs before installing the new rotors and torque the wheels to spec? How do the other rotors look?

ballinbalt07

I hate to brake it to you guys but that comment right there is wrong.......if the brakes were done wrong they will squeal.....from the sounds of the problem the rotors are warped.....did you spray brake clean on the rotors to clean the shipping oil off of the rotors its a very thin coat of oil they put on rotors from the factory to keep them from rusting and if you didnt spray them off and put disc brake quiet on the back of the pads then there's where your problem lies.......

bsbllscnd970

I have been having the exact same problem with my 07 sedan LT. Except ive never changed out the brake pads. Its very similar to wat the OP was saying about braking, except mine also has steering wheel shake. When i break at anything above 25, the steering kinda vibrates and the brakes make a clunking sound too. Any help? Same thing or different?

BLKLS

sounds like warped rotors. get a dial indecator(sp) check run out, put three lug nuts on to spec torq and turn the rotors by hand and check run out.

make sure the hub was clean, alittle bit of rust can cause a lot of run out.

try getting the wheels balacned, i have seen wheels cause a vibration on braking

it sounds very much like the rotor are not straight.

bsbllscnd970

What if they arent? Do i have to get new rotors?

BLKLS

you could just get them turned, as lobg as they arn't WAY out they will be fine.

RedCoboltSS2008

My dad works at the dealer and he is the salesmen. I noticed on my 2008 with 5000 miles when it was up in the getting the oil change i was checking everything out and i looked at the back rotors on both sides and its got deep notches and i asked the teck and he was like they must have put harder pads on the back but idk. But my front rotors are wearing beautifully and for bout the last mounth or so my breaks sweak all the time no matter wat. I just thought it was just the mositure in the air but the way it is sounding its happing on the supercharged ss to. Anyone with the 08's having the same problem as i am?

nate

Sumasianluv

when u put in new brake pads you have to burnish the brake pads

yellowlightning

I've got a 08 and I've got the same problem. I've got almost 5000 miles on mine too and just when it got cold my brakes squeel bad too. But not at first, about three to four pumps and they have to be almost stopped. And sometimes they don't do it. I also work at a Chevy dealer in parts and I can't find any recalls or tsb's. They replaced the front pads but it started not long after. I don't believe it's moisture or brake dust cuz it rained all day and no squeel! Maybe it's in the rear they ain't checked that yet. I'm getting frustrated and it's freakin embarising trying to look good in your car and squeek! They say it's hard to find the noise and it's normal. I say thats BS and my new car will get fixed (I hope). Anybody else have this problem too besides us??? It's a SS/TC

09slobalt

I go 120+ on the highway like everyday and i slam on the brakes from 120-60.... and the steering wheel starts shaking hardcore and then as u drive normal they tend to go back to shape....EBC brakes are next.... the problem is the heat makes all the cheap factory **** warp like a mother, once they cool off back to shape your close to fine.

09slobalt

I go 120+ on the highway like everyday and i slam on the brakes from 120-60.... and the steering wheel starts shaking hardcore and then as u drive normal they tend to go back to shape....EBC brakes are next.... the problem is the heat makes all the cheap factory **** warp like a mother, once they cool off back to shape your close to fine.

psi2hi

hey guys ..i have brake problems with my 2006 cobalt ss s/c..im driving @ 60 mph and my car vibrates all over the place.if i let go of the gas and put the car in neutral and just coast the car actualy starts stoping by itself..i touch the break pedal and its stiff and the car stops right away..so that tells me that the pads are creatting heat and thats why i have vibration.but why is that??i have 32000 miles aprox. i havent done pads they do not squeek.i dont think its that at least i never had that problem with any other car..could it be air in the system or something else?

Jack Robinson

I have this same problem with my 07 cobalt. I have changed everything in the suspension.. bushings, struts and mounts, rack and pinon, tie rods, sway bar/links, breaks, rotors, calipers, several sets of tires, balancing, alignments, axle seals, and even the steering shaft. The car STILL makes that noise and shakes when slowing down or braking. I had several different people look at it, the last person showed me the CV axle and how it was warped, mind you this has been going on since 40k miles and it now has 118k miles on it. Today the cv axle and hub assembly is getting changed. about 4 or 5 days ago it started making a horrible humming noise like an airplane once hitting 30mph and stays at a constant sound, pitch, and never changes. This morning going around an exit ramp turning to the right I noticed that the humming noise stopped, my indicator to change the bearings, or hub assembly since that is how the cobalt is.

If changing the cv axle fixes the shaking noise I will let you know. I hope it does because this car is driving me crazy