- It is designed to prevent the build-up of pressure or vacuum inside the tank.
- The hole is usually covered by a flap or membrane that prevents fuel from leaking out.
- When the fuel cap is closed, the breather hole allows air to enter the tank as fuel is consumed, preventing a vacuum from forming.
- If the vacuum becomes too great, it can cause problems such as fuel starvation or even damage to the fuel tank.
- The breather hole also allows air to escape from the tank when it is being filled, preventing pressure from building up and causing fuel to leak out.
