Fuel Lines - Sizes - Best Practices

[Wulfman]

OK - Almost done with running my brake lines for the 4wheel discs - Now it's time for the fuel lines.

It looks like there are two sizes that run into and out of the tank fittings. 3/16th's and what is the other size? One runs to the fuel pump and the other runs back from the carb correct?

I've seen all the comments (Thanks Charles) on adding an electric fuel pump. If you do this, do you bypass the mechanical fuel pump and cover it up? Does using an electric pump change the layout of the fuel lines?

Thanks in advance.

[pwrwagonfire]

I know this is an old post but....


When we have done this to our WM300's at work, (and the M-37 we have) you get a 'flow-through' fuel pump. This basically means that the pump dosen't HAVE to be on in order for the fuel to move through it. The pumps (as far as everything I've ever seen or done) is to assist the main fuel pump when needed.

I always use it when starting the truck, and it is also very handy if you start to vapor lock.

We have all of ours mounted on the frame under the drivers seat, right in the main fuel line.

Hope this helps.