Hello I have a 97 Chevy Cavi 2.2l 4 speed automatic. At point when i am braking my front bakes lock up and release kind of like ABS but longer duration causing the car to slide or chirp the tires. i have bleed the brakes already. The car has new rotors, drums, and pads all the way around. i started happening when i was on the interstate and had to slam on my brake sin order not to hit some body that had cut me off. ever since then they will lock and release rapidly at random times at braking. Someone please help its driving me insane.

Does your ABS light flash when it does it?
If so, you could pull out the ABS relay or fuse until you have the time to take it to a mechanic. But your ABS and hand brake light will probably be stuck on.

Not sure but... It could be that your wheel's rotation sensor is going bad, therefore feeding bad information to the car's computer and causing the computer to mistakenly go into anti-lock mode. Sensors can behave badly intermittently, so that could explain why the problem occurs intermittently.

My wife's 1996 Cavalier LS convertible has a problem where the anti-lock seems to kick-in on the rear wheels when we first start it up and back out of the garage. But then the problem goes away after a few minutes. My mechanic said that it's PROBABLY the wheel rotational sensor but he can't guarantee it. He said that if I could live with it, I should live with it unless it morphs into a dangerous problem.