How do I "properly relieve fuel line pressure"?
 

Hi guys,
I feel like a total dumbass. I went to go check my fuel filter and thought I read all the directions. I disconnected the ground, took the lid off the gas tank, and as I take off the line from the filter to the tank and BAM!!!!, I nice healthy spray of gas in my right eye. I guess I was asking for it. Anyways, the massive spray of gas came from the engine end of the fuel line. Is there a release valve of some sort under the hood. My Chilton's manual says, "Properly relieve fuel line pressure", but nowhere does it actually tell you where or how. Meanwhile, I'm gonna have a beer and a smoke :smoke: :beers:

Disable the fuel pump and start the engine and let it run 'till it dies.

Disable by, pulling the fuel pump relay or tapping on the inertia switch.

Thanks for the input, guys, but I finally figured it out. There is a schrader valve on the passenger side fuel rail (kind of like the air valve on your tires). I pushed it in with the cap of a ballpoint pen and that relieved the pressure for the system. Thank god I replaced that fuel filter. After a few minutes when I dumped fuel from the old filter, it was brown. EEEEWWWWW.

Otherwise, There is a schraeder valve on one of the fuel rails above the one of the heads, don't remember of it's driver side or passenger, easy to see and access though. Remove the valve cap and depress the center pin briefly to burp the fuel lines.

I just pull the fuel pump fuse under the hood and try to start truck,it shouldnt start then the pressure is releived.

You guys are going way out of your way. There is a reset button on the passenger side kick board. It even says fuel pump reset on the plastic. Just reach in and press the button, this will disable the fuel pump. Turn the truck over and it shouldn't even run more than a split second. Now your pressure is relieved, change your filter/pump or whatever you are doing in the fuel system and just depress the reset button before you fire her back up.

No need to press shroeder valves, pull fuel lines, etc. Very easy and clean.

kev

Bad news. This afternoon, when I was driving to work, I was passing this jackass on the freeway, I felt a nice jolt and then my CEL started flashing. The engine was shaking a bit and acceleration was terrible. Once I got to my exit, the truck idles fine, but acceleration is very sluggish, and now the CEL is constantly lit. I didn't have time to check anything because I was almost late for work at this point. I'm really scared on what is it. Any suggestions for me to ponder?

Plug launch ??

Bad coil ??? :confused:

That could be anything... did you notice any sounds when you saw the CEL come on?

To others: I wouldn't recommend trying to turn the truck over without fuel. You might cause some damage there... personally, I'll depress the relief valve in the engine compartment... I wouldn't think they would have put it there if it didn't serve it's purpose.

-Flea

Huh? How can turning ove an engine without fuel cause any damage?

You can create a whole lot more damage by pushing on the shreader valve on the fuel rail...............Raw fuel on a hot engine ring any bells?

The shreader valve is a test port for testing fue pressure.

Well, think about running an engine with a lean condition. You possibly could cause the same kind of damage.

Also, external operating temperature of an engine is not hot enough to ignite gasoline. It must be much hotter in order to igninte.

-Flea

;)

Unfortunately, there are a million and one reasons for the CEL to come on! The 3 times for me where... a bad gas cap!, and 2 fault codes that ended up being nothing.
Since you just changed your fuel filter, maybe the lines didn't seat up properly and theres a leak in the line or something.
Hopefully not serious... but you might need to go to the stealership!

:beers:

Well, even worse news. I looks to be the transmission or torque converter, though I haven't pulled the codes (can't find my damn code reader!). Whenever I give it more than 50% throttle, the whole truck shakes and acceleration is sluggish and the tach needle bounces, but when I rev the engine in Neutral, it revs just fine. Looks like I should a shop in any case. DOH

Did you check the fuel reset button?

I'm thinking with a CEL and sluggish condition.....bad C.O.P. I've experienced plug launch...that doesn't sound like your problem or you would have mentioned machine gun like sounds. When I had this problem, it was a bad C.O.P. Let us know how it works out.

Problem solved! Found my code reader and got a 0303 (misfire in cylinder #3). Under further inspection, the plug wire boot was rather loose. I stuffed it back in there and everything seems to be fine. CEL is gone. Never had a plug wire just pop off like that before, but oh well. I'm just glad things are back to normal. Thanks for all your help, guys.

How do you know when you have tripped the reset button and the pump is not working, and then how do you know it has been rest for driving.

I just arived home with a new fuel filter and tool, and I'm trying to kick the reset button. I was trying it with the engine running, but I suppose I can try it without the noise.

Help, the sun is shining and I need to get this job done so I can roller blade with my wife.

Your best bet is to disconnect the negative cable and relieve the pressure from the schrader valve from the passenger side fuel rail. Once there's no more pressure, then you're OK to change the filter. It's alot simpler than the pump reset stuff!:thumbsup:

I'm not having much luck with the reset. I just idled the truck for five minutes while taping the reset switch with a screw driver. I'm about ready to take a face full of fuel if I have to. I'll take a look for that schrader valve, and look up the fuse in the book.

From Haynes Repair Manual

Fuel pressure gauge bleeding method:

1. Locate the fuel pressure test port on the fuel rail and install the fuel pressure gauge on to the Schrader valve.

2. Direct the bleed-off hose into a metal cup or suitable container for gasoline storage.

3. Turn the valve and allow the excess fuel to bleed into the container.

4. Close the valve, remove the fuel pressure gauge and cap the test port.

Inertia switch method:

1. The fuel pump switch, sometimes called the “inertia switch”, which shuts off fuel to the engine in the event of a collision, affords a simple and convenient means by which fuel pressure can be relieved before servicing fuel injection components (i.e. fuel filter). The switch is located behind the passenger’s side kick panel.

2. Unplug the inertia switch electrical connector.

3. Start the engine and allow it to run until it stops. This should take only a few seconds.

4. The fuel system pressure is now relieved. When you’re finished working on the fuel system, simply plug the electrical connector back into the switch. If the inertia switch was “popped” (activated) during this procedure, push the reset button on the top of the switch.

EDIT: You will know if the switch is NOT reset because your truck will not start.

Ok, gentleman and ladies, I have a question.

I had my fuel filter replaced by the dealer the first time. That was because when they undercoated my truck they got a bit carried away and undercoated some of the fuel filer and fittings so I did not want to chance on breaking anything. I let them do it, so if they broke anything, due to their lack of attention while undercoating they would pay for any needed parts.

With that said, I plan on doing my own fuel filter changes from now on. What brand filters do you recommend? Should I only get it from the dealer? Or is there as good or better brands I can buy like from Auto Zone?

Thanks for the information.

o1 XLT Sport,

thanks for posting that info. I did get my fuel filter changed by pulling the fuse out. Next time I will pull the electrical connector though. This was an easy job, and well worth the time. Good idea to wear some gogles. I didn't get any gas on me, but there is still quite a bit in the filter and lines that comes out.

I'm beginning to think my truck is weird. :confused: I've changed my filter 3 times, and this was the sequence of events each time:

1. Insert cheap plastic fuel line disconnect tool into end of fuel line and push.

2. Catch small amount of gas that dribbles out with rag. Prop line up on frame to stop dripping.

3. Insert cheap plastic fuel line disconnect tool into the other end of fuel line and push.

4. Catch small amount of gas that dribbles out with rag. Prop line up on frame to stop dripping.

5. Pry filter from metal clip and put caps from new filter over the fuel filter inlets and place in plastic pan to catch gas.

5. Insert new fuel filter into metal clip. Re-connect fuel lines.

6. Put key in ignition, turn to "Run". Check for fuel leaks. Start truck, and check it for leaks again.

I've never relieved the pressure, pulled fuses, tripped inertia switches, etc. I do let the truck set for 30 minutes or so before I do the change and I've never experienced any pressurized gas discharge, only the typical dripping you would expect when doing this task.

As for filters, I've been buying the Motorcraft units at my dealer for about $12 each.

01 XLT Sport - My truck had a ridiculous amount of undercoating on it too. If you wish to remain halfway clean when doing this job, raise the side of the truck enough to let you slide in and out without having to touch the underbody. Also, spray a rag with WD-40 and use it to wipe the lines and fuel filter bracket before you have to touch them.

Just my $.02...

:rocker:

B-Man,

You are brilliant. so that is what those plastic end caps are for, to keep the gas in the filter while you remove it.

I also wonder about the hose ends. If you remove the fuel line disconnect tool does will the end of the line close and stop fuel from draining out of the line? I seemed to notice that the line came off better if you pulled the hose rather than push on the tool. I have no concept of what is going on with that too, just happy that it makes the job much quicker and easier.


The other thing I noticed is the increase in hp. I filled the tank right away so I could check my mpg change with the new filter. I sqweeked the tires comeing out of the gas station because I gave it too much petal crossing heavy traffic. Looks like the stout 5.4 acceleration is back.

Anytime you have a CEL flashing it means that you have a cylinder misfire. It could be a number of things, but I would check #4 spark plug and look for moisture.

Ok, I just did mine and wanted to put my 2 cents in.
1. spend the extra money and get the metal tool, i would have broken the plastic one
2. it was a pain in the a$$!!!! - now i know why they aren't changed very often:rolleyes:
3. to relieve the pressure, I used a narrow flat head screwdriver to pop the red fuel reset button up, attempted to start the engine and let it die, then disconnected the negative battery cable, i assumed it worked because i didn't get sprayed!
4. getting the filter out of the holder was hard as hell, when in doubt, use a hammer!, that popped it out real good:devil: --yea i knew to be careful with sparks and all, it wasn't as violent as it sounded
-anyway, just putting my 2, maybe 1 cent in, i think i'll let the stealership do it next time!:D

oh, and have a large rag handy to catch the dripping fuel, my new motorcraft filter didn't come with endcaps to put on

I'm wondering if anyone loosened their gas cap to vent the gas tank pressure before loosening the filter connectors? I know it's lessened the dribble for me on other vehicles.

another .02 (and probably not even worth that)

Before I changed mine I asked one of the mechanics at a dealership what they did to relieve the fuel pressure. He just smiled and said, "We turn our heads when we disconnect it."

So I did the same and had the same results as B-man, just a little fuel spilling out.

cbone

Thanks for the information, I'll do that the first time I change it. I had Ford do it the first time in case there was any problems since they "undercoated" it.

I only posted what I did because I have never done it with my truck. I have done it on my older cars and never releaved any pressure. However I didn't know if there was anything different with a newer truck and pressure.

Thanks again for the information. :thumbsup: