Why does the gas pump keep clicking off?

There is a reason gas pumps have an annoying habit of shutting off. Gas pump nozzles are designed with a device on the end that turn off the fuel flow when the gasoline runs back into it. This is a safety mechanism which prevents the gas from coming out and spilling when filling up the tank. Typically, this indicates that the tank is full. However, you may experience an instance where your tank is not full, yet the gas pump is still clicking off. Though this constant clicking off, when filling a non-full tank, may seem alarming, it is not necessarily a major problem.

There is a tiny hole near the bottom of the gas pump nozzle connected to a small tube. Normally air flows through the tube while you’re filling the tank. The clicking noise you are hearing is the fuel backing up in the fill tube. Basically, the gas is coming out of the gas pump at a pressure that is too fast for the car to take in. If the air vapors do not get out fast enough and the tube gets covered by gasoline, a vacuum forms inside the nozzle which will automatically switch off the flow of gas into your tank. If the vent tube becomes kinked or slips down into the fill tube this could be the reason for the clicking issue. The best thing to do is bring your vehicle to a professional auto mechanic, such as Paul Campanella’s Auto and Tire Centers, to make sure that there is not a more serious underlining problem.