2008 Chevy Aveo : Brake Issues - Acts as if i'm riding my brakes..HELP!
 

Everyone,

I have a 2008 Chevrolet Aveo, and I've been having some major issues with what seems like the brakes. 50% of the time the car drives fine. The other 50% it feels like the brakes are grabbing and it's literally like i'm driving with my foot halfway down on the breaks. The car will get close to red-lining and will shift VERY late (obviously since it's fighting as if i'm pressing down on the break).

I don't think it's transmission issues. When the car drives perfectly, there's a bit of delay when I press the brakes but they work perfectly...but when it's driving badly I barely touch the brake pedal and it grabs almost like i've slammed my foot into the floorboard.
Sometimes it's not that bad, others it's really bad and I can't go any faster than 20-30mph. When it's bad, i get out of the car and it smells really bad.

I took it to the auto mechanic that I trust and he did about $500 worth of what seems like really maintenance (complete flush of brake fluid system, changed the wheel cylinders in the rear). I trust this guy, known him for years...he said that it didn't really do it any after I did all that maintenance work/changed wheel cylinders, but a few days after I got it back it's doing it again...just as bad.

I'm at a loss...but need some help.

One thing i've noticed is that every once in a while the car will get stuck in park and will NOT release from Park without me pushing something into the notch by the gear shift to release from Park. i've read a few things online saying that this is caused by the brake switch going out and is relatively an easy fix/not expensive. Could it be that that brake switch is out, and while i'm driving it's shutting down as if it were in park and it's fighting itself?

As you can tell, i'm mechanically dumb. Any help would be GREATLY appreciated!

Did you ever discover what the problem was? I'm having an identical issue!