My overflow pipe which is the white pipe coming out of the house is leaking and the downstairs toilet is making a loud high pitched noise I have been told that this is due to the ballcock is this correct and how would I change that if I needed to?

If anyone could help that would be much appreciated.

I assume the "overflow" pipe is your sewer clean out. If that what it is, than it means your sewer is blocked and needs to be snaked. Also, that "overflow" pipe should have water tight cap. Make sure you install one after you finished your pipe cleaning.

The toilet noise is separate problem. Turn your angle stop all the way Off and back On. If noise still continues, yes, clean your ballcock. Close incoming water, remove ballcock head, clean it under running water in the sink and reinstall.

Would this white pipe be a 4" sewer or 3/4" AC or heater pan drain? If it's a sewer the open up, the cleanout and snake to the street. I'm assumimg that you have a float ball ball cock, (see image). Close the angle stop and remove the three screws on top of the ball cock and pull the float ball and stem assembly up pry the washer out and turn it over, seat it firmly! Before you button up turn the water back on for a second to flush out the supply Now reassemble and test. Noise better now?": Regards. Tom

How would I know if the overflow pipe over my patio is for my a/c or sewer and what do I need to do since it is dripping?