Pontiac Grand prix My anti lock break light is comming on and?

[number7ministries1977]

It sounds and feels like there is gears moving and shifting under the break pettel. Also some times when I use the break it pushes 1/4 way down to max breaking, other times i have to push the break way deep to max breaking. I took this car to a break shop and another machinec shop they said there is nothing wrong with the breaks at all its fine.
and i checked the break fluid to make sure it is full

 

[Mr. KnowItAll]

Well then:

1) You're waiting too long before you apply the brakes.
2) You drive on ice.

So, which one is it?

 

[lemmylarue]

Brakes may have air ln the lines.
probably a bubble at the junction box.
Have them bled. if that doesn't solve it,then look
at the master cylinder as being the culprit.
Also the rotors may need turned(smoothed up)