temporary loss of brakes

I bought this car back in Oct 2015 and for the most part really like it, however whenever I go over very bumpy sections of the road, for some reason the brakes disengage for a brief moment before grabbing aggressively. I can repeat this each time now that I know what causes it but unfortunately I am out of warranty and cannot afford Chevy to simply tell me they can't reproduce it or simply start throwing parts at it. This complaint is to make people aware of my problem.