i had all new pads put on my g5 gt front rotors where replaced and rear stayed but i had new calibers put on. recently when im on the highway ill go to pass a car and ill hit the gas and the car wont move it holds its speed. i have tried to down shift and that don't do much also. the other day i was on the highway and the car started to shake really bad so i pulled over to see if a had a flat tire. tires were fine but i was getting a really odd smell from the front of the car by the rims. then today i was on the highway traffic stopped and i locked up the brakes at about 75mph and the car was all over the road it didn't stop in a straight line and my abs didn't kick on. it feels like the brakes are all messed up front and rears. could there be a reason why and the rear make a lot of noise when i stop.

When it feels like the car wont move on the highway when im on the gas the min a tap the brake it jumps to a stop real quick. it feels like the brakes are freezing or something i just dont know what ones are doing it.

 

did you have your brakes professionaly done? because when you put on new rotors and calipers and new pads, you've changed the whole operating system. Abs really only works from a designated point, the abs recognized how much pressure at a certain point is being placed on the brake, but if you move that point on the brake,your abs will NOT activate. Your brakes need to be balanced. I'm not sure if the cobalt has an adjustable valve in it, but that valve determines how much pressure goes into which brake usually its a 60-40 between the front and rear brakes. When you change the brakes like that, they aren't balances so even though your balance is adjusted for 60-40 it can really feel like 80-20 or 20-80. Which will cause your brakes to lock up very easily.

Best bet, go to a brake shop and have them balance out your brakes and make sure they're set

 

the dealer changed them. ill call them and see if i can get the car in then to look at them.