Electric Fuel Pump By-pass

[bike-maker]

I got my hands on a Carter P4070 electric fuel pump that I want to put in my fuel system in addition to my current stock lift pump. My plan is to Y the fuel supply line right after the fuel selector valve, and run one fuel line through the lift pump, and the other through the electric fuel pump, then Y them back together at the inlet to the fuel filter. I also scored some check valves for each leg.
Running the two in parallel like this with check valves will allow me to run the truck primarily off of the stock lift pump, but be able to run off of the electric in case the lift pump dies or to prime the system. My question is where to put the check valves. I was thinking one right after the electric pump, and the other right after the Y right before the electric pump (making them both right after the fuel selector valve).
Your thoughts?
I know at least one of you is running a similar setup (Midnight)

 

[MIDNIGHT RIDER]

I put my check-valves directly in the outlet of the electric-pump and the outlet of the mechanical-pump; thus, neither pump could push fuel backwards through the other.

If you are running a stock-type diaphragm lift-pump, it is also a very good idea to put a cut-off valve ahead of the mechanical-pump's inlet; thus, should the diaphragm rupture and allow diesel into the crank-case, you can shut OFF the valve and prevent the electric-pump from pushing fuel through the rupture.


You are gonna like that dual pump set-up and it's many advantages.

 

[bike-maker]

Sweet, I've already got a nice ball valve to use for this. I think I'm going to ditch the fuel selector valve to 2 separate manual valves while I'm at it - one for the pressure side, 1 for the return.
Thanks for the reply.

 

[MIDNIGHT RIDER]

I'm going to ditch the fuel selector valve to 2 separate manual valves while I'm at it - one for the pressure side, 1 for the return.

That's even better.