Silly question, do you expect fuel to continue to run with pump/ignition not on? Heck its not supposed to run for more than 5 seconds even with the key on, unless the engine starts. Should have a oil pump safety switch in front of it. With no oil pressure it should only run for short period of time even with ignition on. It will only run when cranking or running for more than 5-8 seconds.

Line is pressurized from the last time the pump/engine RAN. Thats where pressure comes from. Line-system-pump, holds fuel pressure so it doesnt have to pump it up all the way from the tank every time.

Tank may have expansion pressure from it sitting, sun helps. This is not present when running because its removed by proper venting through the canister at the proper speed. Used to be all vacuum controlled, is now also electronically controlled. Perhaps will not relieve at Idle, takes higher normal running speed to activate tank vent/filter system. This is good reason for removing gas cap.

The valve does relieve the pressure and is also a hookup for the proper measurement of fuel pressure. The size is the same as that found on mobile measuring systems.

Its really not that drastic to spill some fuel as long as you stay out of its way. Well maybe if you're a chain smoker?

 

"Silly question, do you expect fuel to continue to run with pump/ignition not on?"
Not so silly after having a tank want to siphon out on me changing the mechcanical fuel pump on my 72. Used vise grips to hold back the fuel but didn't relly like doing that to the line. At any rate, I still don't see hold all or what was relayed will prevent the natural occurance of siphoning because the filter dos sit below the bottom of the fuel tank. The lines on this newer vehicle seem to be not just the rubber fuel line like on the 72'.
So,.... if I take off the cap, try and release any pressure at the Schrader, then replacethe cap, duz yahz think that combo will have any effect in helping keep any fuel back that might still want to find it's way out, that is if it might even be able to. I don't see where that has been determined or not at least the way I have been understanding this... Seems there are differences of opinions here. Hell, I don't know, I'm just gonna pull the cap, see if I can release anything from the Schrader if I can reach it, then crack loose the filter. See what happens....

 

Your 72 was well vented even with the cap on. So replacing the cap would not have prevented anything. If it was going to siphon fuel, it would have under ANY circumstance. I have never had one, even an old one do this. They ARE designed to actually have the pump below fuel for priming purposes, but to have it lose a tank of fuel or even POSSIBLY a whole tank of fuel has never happened to me. Perhaps I just had the new one ready and bolted in place before removing the feed line.

As I recall, this is what I did. I left the feel line attached to old pump and mounted new one. Attached line to carb. Moved feed line. I did cheat, if I remember correctly, cause I was alway worried about the connection NOT coming lose. I would loosen it to see if it would come loose and then tighten back up gently to stop fuel. Line was ready to move FAST.

I no longer have any mechanical pumps here. Even my 68 has an electric fuel pump, and that one is gravity primed on the outside of the tank. The first access to it is designed properly and is ABOVE the pump level. The filter is ABOVE pump level. So I guess, on my very own, I built that one to not siphon.

Where is the fuel filter on the 2000? Thats the one you're discussing right? Is it under the car? You mention it being BELOW tank level. Have had some under car and the last one I changed on my 2.5 was in the engine compartment, well above the fuel level of the tank. On any fuel filter, I dont think I ever do the job without having the next new part in my hand. I dont know if I am just expecting to get gas on me and have given in to that scenario beforehand. If I am working on fuel, I expect fuel. I get it on me. I have still not ever had a low fiter siphon on me.

KNOW whats worse?? I react to gasoline, I get a slight fever doing a filter like that, even from the small amount in the filter. Am actually allegic to oil products to some extent also. I still expect a certain amount of fuel.

I do always have all materials with me and work right away to replace it quickly and get the darn fuel on and OFF me as quickly as possible.

If I were you, I would very carefully follow the advice of releasing pressure, venting tank, replace cap and then loosen the line and stand back. Notice loosen, not remove. let it drain out some fuel and see if it stops. Nothing is perfect, fuel WILL come out of there. The filter alone has a small amount of fuel present in it and it will come out. A rag or towel can be used to catch this as per previous post and Haynes.

Make darn sure you are working on a cold car that has NOT JUST BEEN DRIVEN. This alone may well be the reason I dont have problems, I always work on this junk first thing in the morning. No hot sun on tank, less fumes, etc.

 

Electric fuel pumps have a check valve to stop gas from flwoing back into the tank. Reason you have to relieve the pressure.

Like someone mentioned, screw driver to the schrader valve and a rag to capture, I didn't use a rag. Figured it would evoporate faster and I wouldn't have to deal with a rag soaked in gas. It has to be properly dealt with or it could catch on fire all by itself. I also removed the gas cap and left it off. The only gas that drained out of the lines was left in the lines and fuel filter, no way to get around that. I used a old cookie tin to catch the gas that leaked out. Not like your going to strike a gusser. A 1 second stream is about it. Old coffee can works well too, drop the old fuel filter in it once you get it off.

If you dont smoke, you could let it drian onto the ground and let it evaporate.

Disposing of the gas can be the biggest problem. Several options, not all of them legal.
Pour it into your mower, or gas can for your mower(s).
Pour it in the yard to kill any unwanted plants (not legal and don't let the EPA catch you). But very effective at killing grass next to the fence line for the season.
One thing I do not recommend is attempting to burn it. Gas fumes explode, they do not go up in flames like girl scout water (lighter fluid), they explode.