Recently I changed the brakes in my truck. When I slow down (normal, even light pedal pressure, not panic stop), at about 10 mph or so I get a slight vibration in the brake pedal (as if the abs is being activated). It does not last long, but does it about half the time. More concerned about wearing out the ABS more than anything else.

Why is this happening?

 

Might not be the ABS...I had an issue with a similar vibration in my truck after the brakes had been changed out. I couldnt get the front discs off myself so took the truck to a local shop. SHop had to beat the crap out of the right front disc to get it off. In the process of doing that they bent the dust shield behind the right front disc. When they put the new disc on the dust shield dug into the new disc and gauged the crap out of it. Causing a vibration in the brake pedal.

Maybe something similar to what you have going on.

 

It definately feels like ABS.