Safety is very important when preforming fuel system maintenance.The fuel system is under pressure. Fuel pressure must be relieved before performing service procedures on fuel injection system components. Failure to conduct fuel system maintenance and repairs in a safe manner may result in serious personal injury.
Disconnect the negative battery cable. Unbolt the retaining screws and remove the protective shield for the fuel filter (if so equipped).
Place a pan under the delivery pipe (large connection) to catch the dripping fuel, then SLOWLY loosen the union bolt to bleed off the fuel pressure.