I've been having a problem with my brakes for a little while. I've tried a number of solutions but the problem still persits. What happens is, under heavy braking, the whole car vibrates. I can feel it in the pedal but not the steering wheel. It seems like it's coming from the front driver's side of the car but it's hard to tell since the whole car shakes. It's kind of a chattering motion that reverberates throughout the car. I've tried the following things to fix it:

• rotated tires / made sure there was equal tension on all tires
• bled brakes (flushed all 4 wheels, used about 1qt DOT4)
• New pads
• New rotors (power slot)

This is starting to drive me mad! A friend told me that it could be a problem with the wheel bearing(s) and/or caliper(s), though I've already spent a lot of money on this and I can't afford to just keep throwing money at it. Fortunately those parts are covered under warranty, but that means I have to lose my car for a day or 2, and if it turns out not to be those parts, then I could be screwed with a huge mechanic bill.

Any insight would be appreciated!

Do you have ABS? Try taking the ABS fuse out and see if that fixes it. If so, you have an ABS sensor or connection gone bad.

Thanks for the quick response! I'll try that probably tomorrow evening when there aren't too many cars on the road. That would piss me off if it was something that simple -- I've spent a ton of money and time on this already trying to fix it. . .

Just took it out for a spin w/ both of the ABS fuses removed (inside cabin & under hood). The problem actually got worse (ABS did not release brakes when it started shaking so it shook violently) so I guess that eliminates ABS as the culprit.

To provide some background information:

This is a 2000 Cavalier 2.2L. About a year ago I had an ABS issue, brought it to the dealer and they ended up putting a new wheel hub and speed sensor on the rear drivers side wheel.

As previously mentioned, the problem seems to occur mostly under heavy braking. It is not very consistent, i.e. it does not happen every time I brake heavily. Sometimes it goes nice and smooth. It seems to happen most while braking going down hill at moderate speed (such as stopping for a red light at the bottom of a hill). Sometimes it happens on flat surfaces, and it has even happened at least once going uphill at low speed.

Here's an update for anyone who may be interested.

I had new rear drums put on. The mechanic who put the drums on also checked the lateral runout on the front rotors, and said the calipers and wheel bearings look good too. I'm really at a loss here, but i'm going to bring it to the dealer tomorrow morning and have them take a look. I was somewhat relucant because they always give me a hard time about @!#$, and last time I went there they told me there was nothing wrong with the car and charged me close to $300 (car broke down less than an hour later, brought it to another mechanic who discovered it was a faulty fuel pump).

Anyway i'll keep this post up to date after I get the car back from the dealer in case anyone else has this problem.

I brought the car to the dealer this morning. Huge mess. My tire got deflated about 3/4 way through the test drive and got totally torn up, so I have to wait a few days for a new one to arrive at sam's club (Goodyear Assurance, which they don't normally stock).

Anyway, before the test drive, the mechanic said that the rear brake shoes were too tight. I know the shoes auto-adjust when the parking brake is applied, but do they adjust both ways (i.e. will they loosen up if they're too tight?). I'm guessing probably not. Therefore would it make sense to take the drums off and try to turn the adjuster back? I only have the donut tire for now but I can at least get the adjustment down and try it out as soon as I get my new tire.

Hey,

I have a 2003 cav z24 and have the same problem along with another one where the car makes sqeeking sounds from the front when driving between 2-50km/h when NOT braking and NOT turning.... Only happens when crusing in traffic... I hate iT.

When braking hard i feel what you feel. I changed the disks and pads about 30,000km ago but I am thinking its my back drums that need replacing... I got 125k on the car now... Never looked at them.