blue-ss-camaro

My abs brakes kick on for no reason when I am going over rough surfaces like through grass or up a trail. I am not on the brakes most of the time i am in the gas alittle bit and I am not going fast, maybe 10 mph. I have cleaned my abs wheel speed sensors and this did not help anything. I can hear the pump running and I put my foot on the brake and it shuts off and then comes back on a few seconds later. I am thinking about replacing the wheel speed sensors. any thoughts???