I installed new Hawk pads and they work great but when I am in traffic or accl. slowly and apply the brakes there is a cracking sound each time the brakes are pressed. Any idea what this could be?

 

No matter what it is you will need to pull the pads back out and inspect them and your installation job, so that’s what I would do first. Check for anything obviously out of place, maybe you somehow have the retainer clips on wrong.