Getting clunk type sound when braking hard

Garys72Duster said
My 70 Dart was doing that when I bought it. Checked the front calipers, and the left one had a loose bolt! Tightened it up good, and the sound went away. I've seen this happen more than once. Double check and re tighten the caliper attaching bolts.

I will give that a shot. If that's not it I'll check and re tighten everything I have done previously. Thanks