Technology has created a system for coupling fuel and oil lines that far surpasses Henry Ford's old tried and true method of a hose clamp and a screwdriver. While his hose clamp method worked, it was typically difficult to tighten and loosen depending on where the clamp was indexed. Ford's new fuel line compression fittings are easy to assemble and disassemble. Best of all, it can be accomplished with only a single tool for both supply and return lines.
Park the vehicle. Apply the parking brake and open the bonnet. Disconnect the battery by loosening the negative battery terminal with a wrench.
Identify the fuel line fitting. Modern fuel systems are made up of two lines. A supply line and a smaller return line. These can be found at the rear of the fuel log on the intake manifold. They are typically comprised of a hard line coupling to a soft rubber line.
Insert the tool. Place a clean rag under the fuel line fittings to absorb any fuel that might escape from the fittings as they are disconnected. The fuel line tool is made of plastic or aluminium depending on the cost of the unit with plastic being least expensive. The tool slips around the fuel line and protrudes into the fitting. The tool will typically come with two or more sizes to allow it to be used on both the larger feed line and the smaller return line. Begin by inserting the tool into the larger feed line fitting.
Separate the fittings. Apply steady inward pressure to the fuel line tool causing it to slide into the coupler fitting. You will feel a slight give when the fitting has been depressed enough to separate the lines. Pull the two fittings apart and repeat the action to the return line.
Reassemble the fittings. Make sure that the rubber o-ring is in place on the fuel line fitting (male side) and lubricate the o-ring with a drop of oil or fuel. Place the male end of the fitting into the female end and push the two together until you feel and hear the two snap together. Replace the battery terminal and tighten the bolt with a wrench. Close the bonnet.
Allow the vehicle to sit prior to disconnecting the fuel line fittings. This will allow the fuel pressure to bleed off and avoid a large fuel spill.
Never work on a fuel system while smoking. A fire and serious injury or death could result.