how do i know the fuel pump is going bad in a 1998 ford expedition eddie bauer?
fuel filter is recommended to be changed every 15,000 miles
You just don't know until a mechanic tells you.
check the the pump pressure at the rail
Just replace it.
If the fuel pump becomes noisy you can rest assured it is going bad. But, the pump maybe going bad and not make any noise at all. Anytime you have a problem with fuel delivery, first thing to do is replace the fuel filter. After replacing the fuel filter a fuel pressure test will verify the condition of the pump.
When a fuel pump is bad the vehicle will not start. A fuel pump that is going bad may cause the vehicle to shut off while going down the road.
Noisy pump, hard starting, stalling.
Swap the relay with a another like relay.
Well, if the fuel sending unit is going bad, it will either send too much fuel, or not enough. If the truck fails to start, or if it struggles to start and then smells rich in warm weather, you've a problem.
You will not know. That is why you just change it according to the manufactures recommendations as listed in your owners manual.
Hard starting, stalling and eventually it simply will not run. Change the filter before assuming the pump is bad.