Hey i have a 2000 sunfire 4 door and i have a bad Klunksh noise in my rear brakes. when i hit the brakes it goes klunksh and it feels like they are sticking together,and then when i let go of the brake they release. this only really happens when i take out the car for the first time of the day and ussually only in reverse . i have ABS, but when this happens the ABS doesnt work and my tires just lock when i hit the brakes and the right rear suspension goes right down as if it was shot or just totaly broke but later i checked my suspension and they are just fine???

Sounds to me that your wheel cylinders are leaking brake fluid on your shoes. Have the same prob on my Sunbird.

I have the same problem... But i know for a fact my rear struts are blown so thats my guess on my problem... I'm just about to the point on giving up on these damn things.... Rear disc conversion