This occurs in the automated nozzle petrol pumps. All people think these vehicle pumps are tamper proof but they truly are not. The auto nozzles have a nozzle trigger lock, which when activated, stays on till there is flow of fuel in the pipe and mechanically pops off when the fuel flow stops. The technicality is – it’s not impossible to override the trigger lock.
This is how this petrol pump scam occurs:
He/she sets the auto trigger on and then fits the nozzle into the petrol tank. Eventually the meter stops running and the attendant takes the nozzle out. You might be joyful because you saw the meter reach ‘x’ liters without an ogre interruption. But the scam poor you is just not even conscious of it and has occurred.
The attendant is supposed to take his or her hands of the nozzle after setting the auto lock and touch the nozzle again just after there is certainly an audible ‘Click’ from the nozzle, which suggests that the process that was pumping has ceased.
There is a time lag of 3-4 seconds between the meter discontinuing and automobile nozzle . The pump keeps sending fuel in these few seconds (in spite of the meter ceasing) because it needs to empty all the fuel which is trapped in the connecting tube and the meter has billed you for it.
But our intrepid attendant has other strategies. Because you were glued to the running meter you did not find it, but the attendant never got his/her hands off the nozzle. The moment the meter stops running, the attendant throws the nozzle away and overrides the auto trigger. Some of the fuel is still trapped in the connecting tube. The fuel tube is then maneuvered by the attendant and places the nozzle in its holder.
The maneuvering would be to make certain all that cornered fuel (your fuel) is sent back into the tanker, thus emptying the connecting tube (in the reverse way). A ‘skilled’ attendant can siphon off 50-100ml per filling of fuel.
That might not seem much but it adds up at the end of a busy day, at the expense of thousands of victims like you. That is the ‘No Click’ trick. You never heard the clink and you never will, provided that the attendant has his or her hands on your own gun trigger.