A fuel line is essential to the proper operation of any gas-powered vehicle. The purpose of the fuel line is to keep the fuel contained as it is moving between the tank and the engine. If the steel line is cut incorrectly as it is being replaced, it could allow fuel to be released, causing permanent damage to the car. Basic knowledge of cars is important when attempting to cut the line, but it is a project that can easily be done at home.
Find the fuel line that will be cut. Select a spot to cut the line and mark it using a piece of soapstone.
Turn the bottom knob on a pair of tubing cutters counterclockwise. This will open the jaws of the cutter. Only open the jaws enough to fit the fuel line in between.
Slide the tubing cutter over the fuel line. It should now be in between the cutter's jaws. Center the jaws on the mark made by the soapstone. Turn the knob on the tubing cutter clockwise, forcing the jaws to close on the line. Turn the knob another quarter turn once the jaws are touching the surface of the tube. This will apply pressure to the fuel line.
Turn the entire tubing cutter two times around the fuel line. Tighten the cutter's jaws again by turning the knob on the cutter another half turn. Turn the cutter another two times around the line. Tighten the jaws again. Repeat the steps of turning and tightening the cutter until the cutter breaks the line.
