OK, I'm hopefully dropping my tank to put in a new fuel pump this weekend (I know, it's way easier to cut a hole in the floor, I know... I just refuse to do it!!!) and in the process I'm putting on an SLP Loudmouth cat-back.

Question I have is... How do you drain your tank when your fuel pump is completely dead??? I know some people siphon, but I haven't had much luck with doing this with newer cars... Plus you always leave a few gallons in there that you can't siphon.

What I used to do on carb'd vehicles was leave the gas cap on, pull the feed and return lines off the pump, and apply air pressure to the fuel return line. Not much! I don't think the gas tank was designed to hold 120psi!!! But I'd just stand there and put a little pressure in and wait for the flow to stay steady out the feed line, and when it started to drop off I'd put a little more pressure on. Beats the hell out of sucking on a siphon hose, and you get the absolute most fuel out that you can, since you're pushing it out with pressure.

I've never tried this with a fuel injected vehicle though. I know it must work in theory, because my pump is completely dead, yet if I leave the fuel pressure gage on the fuel rail for a few days, it will fluctuate with the ambient temperature, so on a really hot day it will go up to about 5psi and drop back down to about 3psi in the evening. It's actually enough to start the car for about 3 seconds, and then it takes 24-48 hours to build up pressure again.

Any better suggestions, reasons the above won't work, or tips on siphoning? Maybe I should just drill a hole and put in a drain plug...

Paul 'X'

 

Good Idea, may come in handy in the future

 

Kind of hard to explain, but when i used to drain tanks at this shop i worked at this is how we did it.

We had an old peice of rubbed line, pretty big in diameter. It was about 3 feet long. Insert one end in the filler neck, and hold the other end out. Take an exact knife or something of that nature, and make a slit on an angle until you have peirced the inner diameter of the hose. DONT CUT OFF THE FLAP. Then take your air hose, with the blower nozzle on the end, stick it in the slit, start blowing until the fuel comes out and then hold your thumb over the flap to hold it down.

Now that i think of it, its basically a siphon. But it should drain enough out so that it is really easy to lower. Lets face it, how heavy is a gallon of gas? Plus you are probably going to use a jack or something like that to lower it down slowly.

P.S Dont drill a hole in it, you might not live to use that drain plug

 

6.3 pounds per gallon of gas