Extreme care should be used while working with any of the components of the fuel system. Gasoline is a very volatile and flammable substance. Do not expose it to an open flame, spark, or high heat. Disconnect the negative terminal of the battery before doing any task that releases gasoline from any part of the system. Use containers to catch the gasoline and cloths to wipe up the minor spills. Use a flashlight rather than a trouble light or drop light. Gasoline spilled on a hot bulb could cause the bulb to explode and ignite the gasoline. Never attempt to weld a fuel tank. Even when a fuel tank is empty, it can still contain enough gas fumes to cause an explosion if the fumes come in contact with a flame or excessive heat. Always keep a class B fire extinguisher nearby. It is specially intended for use on gasoline fires.