Vehicle Refuelling Tips

Occasionally I’ve found that the fuel nozzles on some bowsers at service stations seemed finicky in that the automatic shut-off cuts off all almost constantly with the result that it takes ages to fill the vehicle. My usual reaction has been to let the attendant know when paying for the fuel and avoid using that bowser in the future. Recently I had trouble filling the car at the United service station at Cowra. When I told the attendant what had occurred he was most helpful and explained what to do in the future.
The shut-off problem occurs mainly with unleaded fuel because of the safety insert just inside the fuel cap. The purpose of the insert is to reduce the diameter of the pipe to prevent motorists from using the wrong type of fuel. They were installed in vehicles manufactured after Australia made the decision to switch from leaded fuels to reduce the health hazard from the old fuels. The inserts have a small flap that is designed to stop fuel flowing rapidly out of the tank in the event that the auto-shut off does not function properly. The auto-shut off mechanism works off air pressure. There is a very small tube in the pipe at the top of the nozzle that provides the mechanism for the detection equipment to function.
To effectively stop the auto-shut off function from working two changes in the way the nozzle is positioned and used are required. The first is to insert the nozzle so that the end is only just past the small back-flow flap mentioned above. The second it to turn the nozzle 180 degrees from the normal position i.e. turn it upside down. I tried this yesterday when refuelling our utility vehicle, which is notoriously difficult to fill, and it worked superbly.
WARNING: Using the above method turns off the auto-shut off. This means that unless the motorist is extremely careful there is a high likelihood that the fuel tank will overflow, creating extreme risks of the motorists ending up with fuel all over themselves … with obvious fire risks. To avoid fuel spillage the motorist should reduce the flow into the tank from what might normally be the case, ‘listen’ to the sound of the fuel going into the tank and watch very attentively to stop the fuel flow early. When listening to the fuel flow it is normal that the pitch of the sound increases when the tank is almost full. This was the main mechanism we used to rely on before the introduction of auto-shut-off bowsers. It was the auto-shut-off mechanism that allowed service stations to change from having staff available to fill up vehicles to what we see almost everywhere today - self-service.