Only return line to frame rail fuel filter.

[FarmerBoyFPV]

I started plumbing in my 120 gallon bed transfer tank to my 95 12v cummins. I only have 1 3/4 inch drain in the tank and decided to run 3/4 in to my cat style filter base without a return. I didn't want to run a return up to the top of the tank as i also use it to transport off road diesel. I figured by running 3/4 at a decent from the tank any air that made it to the filter head should rise to the tank.
That got me thinking if I only run the return to the filter head and cap the return to the stock tank, it could solve two problems. I can get away with just one divertervalve, and it would completely stop cross tank contamination. No timing the return to hopefully flush all the wmo out ect.
The potential downside would be possable air getting trapped, but should be easy to relieve by selecting the wmo tank until the system is bleed. I just confirmed this to work as I just fired the truck with return to tank intact and filter empty. I made it halfway home and the truck died, I opened the diverter, truck fired right up, back to stock tank and home u went.
Thoughts questions ideas? If it is an issue I thought about using a rollover valve on the filter head to the stock return thinking it would let the air out ect. Or a small orifice like the 6.0 with a dead head pressure from the fuel filter.

 

[ut99dot1]

Hey, I have the same thing and run a T section with at one of the ends a small valve (highest point in the engine). If it needs bleeding I'll open the valve which has a 1/8 hose attached to it (dumping some fuel inside a coke bottle), then close it off again after a couple of seconds. Seems to work well.

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[FarmerBoyFPV]

I'm thinking of adding a water separator filter on the return upside down. Should catch air the same way as water then the drain would work as a purge. But not really needed so far priming the truck has never been easier, had the fuel system apart several times. The tank being so high dose a great job of pushing the air out. If I get a pocket switching the ball valve to oil I hear the tank bulch and the truck fires right up again. Once its primed its good to go, pros are 0 cross tank contamination, the fuel gets passed though the filters in s short loop I suppose warming the oil, and less work on the fuel pump as it doesn't need to pull up fuel from the draw straw. Down side is the fuel dosnt get agitated/mixes with the return flowing back to the tank. I notice gas will float in the top, but I'm planning to pre heat the oil and run it straight with dual tanks.