I recently noticed that toilet supply pipes have started to "clang" when the tank is done filling and the water shuts off. It started when the kitchen sink (opposite side of home) spray hose started leaking and I replaced it. It had been making a cavitating noise and was shuddering, but replacing the spray hose eliminated that. I am thinking that there is air in the lines, since it is not as pronounced upstairs. Is there a way to bleed it out, or is it a symptom of something else like water hammer? House was built in '72.