![Toilet makes hissing sound unless I open the back and press the black piece, which seems to release air and stop the hissing. Any suggestions? : r/fixit Toilet makes hissing sound unless I open the back and press the black piece, which seems to release air and stop the hissing. Any suggestions? : r/fixit](https://external-preview.redd.it/yoWsRVLlXRCKG1ty5--BmtYamy9C4Mk_pFcTX_lBfjk.jpg?auto=webp&s=ae0b9e14cfc3f4a4dccdbf15ecf7cd8cc9cc4b4e)
Toilet makes hissing sound unless I open the back and press the black piece, which seems to release air and stop the hissing. Any suggestions? : r/fixit
![How to Fix Toilet Running Continuously or Making Hissing Sound: Flushing Debris from 400A Fill Valve - YouTube How to Fix Toilet Running Continuously or Making Hissing Sound: Flushing Debris from 400A Fill Valve - YouTube](https://i.ytimg.com/vi/AabLItDN-qk/sddefault.jpg)
How to Fix Toilet Running Continuously or Making Hissing Sound: Flushing Debris from 400A Fill Valve - YouTube
![plumbing - Why does my newly installed fill valve hiss after flushing? - Home Improvement Stack Exchange plumbing - Why does my newly installed fill valve hiss after flushing? - Home Improvement Stack Exchange](https://i.stack.imgur.com/xtVRM.jpg)