Fuel lines feed, or return: Which direction does the fuel flow on upper line?

[dr_how1]

This is an odd question. Does anyone know what direction the fuel flows on each line from the under the frame filter/water sep to the engine? There are two lines, one upper, one below the upper.

I ask this as I was going to try a "Fuel Mule" which is a set of magnets that attaches to the line (easy attached, and does not look like any harm to the line) that is claimed to improve mileage. It has to be set a certain direction, one end facing toward the engine of the line that feeds to the engine (not the return line).

They claim 10%. I have seen this work with about 15% in a friend who has a Caddy STS. So, I thought I would try since this 08 of mine is such a mileage pig. Yes, I know most of the terrible mileage is due to the regen (I hate the feds, then need to be forced to pay us all back for the extra costs of fuel. They are jack booted thugs).

Anyway, if someone will be able to have a confirmed answer, I will try this thing, and report back if it works. Once I find out which line goes to the engine, it will be about a 2 minute install. I would like to do it today if at all possible (nice and warm outside for a change).

Thanks in advance for the help.

08 KR F350 SRW, loaded, 5.3k Miles

[SDdriver]

Don't waste your money on Fuel Mule, but anyway. Look at the fuel separator where the lines go in. There will be an arrow on the assembly telling the flow of each line. On mine Supply was the bottom line.

[dr_how1]

I will check for the arrows on the device.

As for the Fuel Mule, it was given to me by someone who has them on his cars. He swears by them. Do you know something he does not?

I did not believe any of this magnet stuff. However, a company now is selling a home "water softener" that uses magnets. Consumer mag here in town said it did work and affected the molecules of the water. So, you never know.. Might do something to fuel. We will see. It should only take a minute once the bottom line is the supply is confirmed.

Will try to put it on in next 48 hours and report back. Again, thanks for the help. I think I need to keep your contact info around incase I need help with a Lemon law return. Looks like you have had three. When will Ford get it right?..

[dieseldiesel]

If you haven't looked for the arrows already, the lower 1/2" line is the supply, upper 3/8" line is the return to tank.

Good luck with the magnets.