Auxiliary fuel tank gravity feed??

[dirk721]

Tried searching in advance but couldn't find much on this. I was curious if it is possible to plumb in a gravity feed type system into the existing stock fuel tank? I have a 1990 M923A2 and it looks to have 3 different ports on the top of the tank that I believe are the supply, return and vent lines. Can I tap/feed into the return or vent lines and which ones are they? The tank would be mounted in the bed. I will be running an inline filter and shut off valve before it will go into the existing tank.


Thanks for the help in advance!

 

[smittyjr355]

I don't see why you couldn't tap into the return line. My question is are you planing to run with the valve open at all times or are to going to just open the valve when the main tank is low and fill it then shut the valve off once full?