Clunk when going slowly and tapping the brakes?

The brakes and rotors are brand new, and the clips are installed properly, and the caliper bolts are tight and as well the caliper mounting bracket bolts are tight too. It is acting like a ball joint to me. How do I check the lower and upper ball joints? It had the clunk before the new rotors and brakes were installed too. When rolling very slowly and just tapping the brakes there is a clunk and it feels like some suspension part is moving and clunking. Again, while going in reverse and tapping the brakes it is solid with no clunk and no feeling of suspension moving at normal highway driving everything works well accept on initial tap of brakes there is that clunk. Thanks