knocking sound when i brake?

Maybe the caliper is lose, like they didn't tight a bolt. Or even lug nuts not tight. Pad not installed correctly. Drum shoe stuck.

so this problem began before the brake install or afterwards?

if you just got new pads, it could be improperly machined rotors, or rotors that just need to be replaced.

this happened before the new brakes were installed. i'm pretty sure i got new rotors not just the pads. if it was one of the problems u guys stated, how bad is it?

ok, so then why didn't you just ask the mechanic? btw a "clunck" could be just about anything, probably anything we tell you here wont be it. Were all either guessing or talking out of our asses. check your rear passenger seatbelt, its probably jumping forward when u brake and crashing back down when u stop decellerating... see what I mean? not trying to be offensive or anything, I just know that you won't find your solutions online.

yeah i understand. the mechanic didnt seem to know much either. just wanted to see if anyone online had any input. and this knocking/jackhammer sound i hear i could also feel when i'm pushing the brake down. i could feel it through the brake pedal kind of.

check your cv joint, may be the boots are crack and the joints are drying out.