front left break rubbing/popping noise?

My car just started making a noise when im driving at very low speeds that sounds like something is rubbing on something else. also sometimes when i press on the break peddle it will make like a popping noise and there wont be any breaks and ill have to press it in almost all the way to get the breaks to work.....Any ideas?

Its only coming from the front left tire. I just recently replaced a wheel bearing on it so maybe something got put back on wrong?

well if your brake pedal is popping i think maybe the slave cylinder is worn out or the master cylinder

i got the same noise lol and it was kinda popping too but i replaced the front motor mount and the popping stopped..but the rubbing/grinding is still there...