From what the Fuel Pressure Regulator instructions said all you have to do is open the gas tank lid, though there will still always be some pressure so keep a rag aound.
How do you depressurize fuel system to install filter 1998 ford expedition?
No, but it is safer if you do.
Pull the fuel pump relay in fuse box under hood and try to start car.
Remove gas cap and suck all gasoline from gas tank.
depressurize the fuel system by unplugging fuel pump fuse and run till it dies. disconnect top hose and "T" in with a fuel pressure guage
Remove the fuel pump relay from the under hood fuse box and crank the truck until it doesn't try to start.
fuel filter should be located inside engine compartment monted on fire wall.remember to depressurize fuel system and DISCONNECT battery when doing this.
AnswerWith the engine running, pull fuse #1, the fuel pump fuse. Let the engine run out of gas.
to depressurerize the system you would simply take off the gas cap.(fuel will still be in the lines and it will spill when the lines are disconected but it would not be under pressure)
open the gas cap
Remove the gas cap. Unless there is a Schroeder valve on the fuel rail, you will just have to remove the fuel line at the fuel filter to relieve pressure. Wrap the connection with a rag while removing it and be prepared for the spray.
Look for a Schrader valve on the fuel rail and press it to relieve pressure. If there is not one remove the fuel cap and then be prepared for a small spray of fuel when you disconnect the filter. Place a rag around the connection before disconnecting it.