Pinging sound left front wheel

Recently my 2007 Prius has developed a pinging noise which seems to come from the left front wheel. At first I thought it was the axle which I replaced a year prior so while still under warranty I replaced it again but the noise still remains. The loud ping will happen usually after braking, another words when stopped at an intersection then accelerating after the brake is released. Also noticed that it doesn't seem to do it while in electric mode or when engine is running. My thought is maybe the caliper is hanging up and then releasing. Also thought it could be a wheel bearing or strut but it seems to be happening after braking. I do have a little vibration from that wheel at higher speeds but it doesn't shake while stopping. Any input would be appreciated.