[kro]

I've had my truck for 6 years and have wondered about how you get an equal amount of fuel conditioner in BOTH tanks and mixed evenly. When I fuel up I put in a shot then fill till I think the rear tank is full then when I think its headed to the front tank I put in the last shot (I have one filler neck for both tanks, it is an E). I've often wondered if when the fuel comes back from the ip if it goes to the tank from which it was taken - I assume so.

Any fillup tricks out there that might help us all?

 

[argve]

Never seen a dual tank E series before...

 

[kro]

It's an odd duck for sure. It was a former motor home now a flatbed. A couple of kids stole it when it was a motor home and totaled it. I bought the cab and chassis and made it a flatbed. In '99 when I got it it had 7,000 miles, yes 7,000. It now has around 50. Pulled a 5er to florida twice, camper to Mexico once and off this month to Alaska with another camper.

It has a rear tank and another along the dirverside frame rail near the cab. One filler neck at the back puts fuel into the rear tank then when full it backs up, goes down another long pipe to the front tank. The y in the pipe is too far down from the filler to get a hose to snake down and squirt a shot of additive into the front tank. So, I have just put a shot into the rear tank, fill it, then put another shot in and hope it gets carried to the front tank. Not a very accurate method. I just thought others might have had this problem. I know the E form should be the place but the E folks go here too for the 6.9.

 

[Aubrey]

Here's a thought. Since you have a shared filler tube that will allow fuel to transfer between tanks, and the fuel system is a continuous running loop driven by the engine lift pump, why not reverse the return lines to the opposite tank? As you drive, the return fuel will drain to the other tank and vice-versa with overflow exchanging via the filler tube and thereby mixing the contents as one. I guess it would depend on how high the filler Y is mounted to ensure it cross flowed instead of escaping out the tank vent (if any).

 

[kro]

Aubrey:
Very interesting idea! I wonder if when both tanks were full and the return line had to push against a full tank to push fuel back out, up the filler neck and into the other tank it would result in too much back pressure to the flow of fuel?

 

[Aubrey]

I don't expect that would be a problem; no more than full tanks in a stock system. The return line is always downhill, starting at the fuel filter which is higher than the filler Y.
I don't know how fast the stock return system will circulate fuel back to the secondary tank. But my basic idea is to continuously push fuel from the original tank where the additive is, into the new tank which would then spill back to the original tank via the Y. If you can't get enough flow from the return system, use a cheap electric fuel pump. Draw engine fuel from the stock tank first in order to use additive while the cross-mixing occurs.

 

[ZOP]

....instead of jerry rigging it even further....it might be a better idea to get a second filler on it.