Brian 96 Z28

I have a 96 Z28 Auto with about 146k miles and when I brake lightly I hear something vibrating and the car shakes a little. This doesn't happen with heavier braking or if I just use the e-brake.

This has been happening about a month or so and I originally thought it was rotor warp but I just installed new Powerslot rotors and Hawk pads on the front and the problem persists.

Any ideas on where this is coming from?

93Z286Speed

well due do it not happening when you use the ebrake that kind of isolates it to the front of the car. Its still possibly from the front brakes, New rotors arent always perfect. and when you put the new ones on im sure the hub was rusty. Its always a good idea to clean the hub off as best you can to ensure a flat mounting surface. Thats probly where id start. And possibly check the balance on your front tires. On the front brake issue theres something GM uses called Brake Align and what it is, is a way to measure LRO or Lateral Run Out of the rotor. It checks to see if the rotor is spinning true and takes into consideration the base of the rotor along with the mounting surface. Basically what it is a shim set used behind the rotor to get the LRO at or under .002. This is measured with a dial indicator. If thats something you have laying around id probly check that before you pull the rotors off just so you know if you found a problem, a little peace of mind.

Brian 96 Z28

Thanks for the suggestion.

I've actually done some more testing and I'm able to get the vibration and the rattling noise and low speeds when driving on rough roads or bumps so I think I may have mis-diagnosed the problem. The noise is coming from the passenger side rear of the vehicle and it's not the hatch.

Could this be a wheel hop problem?

OBE1 95Z28

Wheel hop is typically experienced under heavy acceleration from a dead stop. Sounds like you could have bad rear shocks or loose rear suspension components such as the lower control arms. Check to make sure your rear suspension bolts are tight and look for leaking fluid around your rear shocks.