How do I cure the wistling noise post flushing the toilet

Did you make sure your water supply valve is fully open? Have you done any work to the toilet recently? How long have you had the noise when you flush? If your supply valve behind the sink is fully open, try flushing the fill valve,

https://www.bing.com/videos/search?q=Fluidmaster+400A+Troubleshooting&Form=VQFRVP#view=detail&mid=DBF7B1177EC847A6DE7DDBF7B1177EC847A6DE7D

Let me know if that works for you. If not, you may have to replace the fill valve. It's cheap, and easy.

Hello Jac Jug,

Please answer Talaniman question, may be you have debris inside the fill valve it needs to be flushed, Thanks.

John

Agree with above posts: remove Fluidmaster head and clean under running water. Reinstall. Also, Close and fully Open angle stop under the toilet. See if that helps

Milo

Here is how to flush the debris out of the fill valve, see the images, Thanks.

John