Does anyone know if the valve/filter in the attached picture is directional? I would like to add an external filter and just utilize as an open vent (in and out). I would like to know for sure, perhaps someone has one on a bench that they can blow into for me?

I am looking to eliminate the other 3/8 vent and utilize as a second return line back to the tank. My current 5/16" return line is too small for my upgraded fuel pump and I can't regulate the pressures down to where they need to be.

 

That is a roll-over valve. It plugs the vent line if the car goes tires up.

It does allow venting in both direction as long as the shiny side is up.

It can't be used as a return line as there is a restriction in it. And a return line needs to go to the bottom of the tank.

RBob.

 

The fuel pump is large enough that I planned to utilize the 5/6" evap line from the front to the tank with an adapter to the 3/8" vent (it doesn't have a valve on it) along with the current return line to return fuel to the tank.

If 1/2 the fuel is going to the bottom and 1/2 is returning to the top what issues could I run into? I would think that if I wasn't low on fuel I should be fine?

 

OK, that makes sense. As for returning to fuel to the top of the tank. It tends to aerate the fuel in the tank.

RBob.