Guys, on a 98 F150 4.6 115K miles ... I want to change the fuel filter . I see in the owner's manual a fuel pump relay in the box under the hood. Can I remove the relay ( will the truck start ) and let the truck run to de-pressurize the system. If not, please offer other suggestions or recommendations ... thanks ... sdtsdt

 

You can relieve the fuel pressure by bleeding the fuel from the test port (schraeder valve on the passenger side fuel rail), keep a rag handy because some fuel will squirt out.

You can also disconnect the cable from the inertia switch (behind the passenger side kick panel) and then run the engine until it dies. To restart the truck just plug it back in and you might have to press the button if it popped out.

 

just let it sit overnight and it will bleed off.

 

just pull the fuel pump fuse and start it,i think its #15 or somethin but its in the owner's manual.simplest way to disable the fuel pump

 

Yeah but make sure you have a large towel handy because when you pop open that filter you'll think it started raining so don't be dirrectlly under it

 

Thanks guys . i pulled the driver side kick panel and unplugged the inertia switch ... it was easier to get to than I thought. The real kicker was getting under the truck and discovering that I needed a fuel line tool .... I elected not to try and force it and I went to Pep Boys and picked up a tool for $6.99 ... Still, I have 115K miles on my truck and this is the first time I elected to change the filter. Don't you just love these one time tools ?

 

I would think you'd want to use that tool a little more often than once in the life of your truck

 

One time tool? I use mine every third oil change to replace my fuel filter!

 

I also have a 1998 4.6L. The manual recommends fuel filter change at 30K for NORMAL conditions and 15K for SEVERE conditions. I have mine changed about every 20K. I went 30K on the first one and found out it was very dirty. I have gotten better since than.
Good luck.

 

I have a 1998 F-150 4.6L with 119k miles and I've never changed the fuel filter..

I got a 100k mile service, but I don't remember them mentioning this..

If indeed I have my original fuel filter is this bad? My truck runs great!?

 

Like ANX, I never had any noticeable problem or symptom ... Still, I finally broke down and changed the filter. Guys who have not done this, you need a special 5/16 in tool to release the filter ... Also, I changed my trans fluid and filter for the first time ... I used the process of draining torque converter as well as dropping the pan ... It took a little over 12 quarts to replenish ... I put in news plugs recently and new air filter ,,, so, today, when taking my son back to college, the check engine light comes on !. I guess my truck doesn't like clean gas, clean air, and smooth shifting ... I suspect that it is a O2 sensor ... I will have local auto parts store pull the code tomorrow ... ! Oh yean, and I'll pick up a new PCV ...

 

change filter every 15-20. The secret to long fuel pump life in fords is change the filter often

 

Also don't run around in the summer heat with less than a quarter tank all the time....the fuel is what keeps the pump cool...if it's out of the fuel it gets hot and prematurely fails

 

Question. Does a new fuel filter improve gas mileage? I hope this is not as dumb of a question that I think it is.

 

When I changed my fuel and air filters at 20k miles, I picked up a little over 1 mpg in fuel mileage. I also cleaned the mass air flow sensor but I think the most benefit came from the new filters. I used NAPA Gold series for each.