The term TIRE LEAK SOUND can be summarized by three crossword solutions: HISS (4 letters), PSS (3 letters) and SSSS (4 letters). HISS is a sound made by a snake, which is often used to describe the sound of a tire leak. PSS is a sound made when air is released from a tire, which is also used to describe the sound of a tire leak. SSSS is a sound made when air is escaping from a tire, which is also used to describe the sound of a tire leak.