How and where are fuel injectors lines that need to be cracked or loosened to prime fuel lines on a 2003 ford f-250 7.3 powerstroke?

To prime the fuel lines on a 2003 Ford F-250 7.3 Powerstroke, locate the fuel injectors on the engine. You will need to crack the fuel injector lines at the injector ends, which are typically found on the top of the engine, near the valve cover. Use a 10mm socket to loosen the nuts on the fuel lines, allowing air to escape and fuel to flow through. After loosening, crank the engine to help prime the fuel system, and then retighten the lines once fuel begins to seep out.