Hi All
I just put in an auxiliary fuel tank in my 15 f250 but I have questions
The previous owner had a tank installed and left the hose plugged in the bed Soni got a transfer tank and hooked up to the 3/8" drain plug then
I hooked up a selinoid to my uplifter switch to control the refill but when I turn it on it barely trickles into the filler tube.
First question
Do I need a valve or can I just hook it straight to the filler connection?
Second question
Do I need to change out the filler cap or are all of them vented
Thanks

 

Not knowing the type and brand of your transfer tank I don't know if yours has a vent on it. I have a custom built transfer tank and use an electric fuel pump to suck the fuel out from the top and into the fill spout with a tee fitting installed in the fill hose. I don't like solenoids due to the heat they produce and current they draw and use a U.S. Solid motorized ball valve because once they are open the current draw is very little and no heat produced. I use a non vented fill cap but the tank is vented with a roll over valve. If you are using gravity to flow fuel you must have some type of vent on the tank. If you don't use a valve on the discharge you'll overfill the tank.

 

This is the tank I have
ATI Fuel Tank Transfer Tank Part #: TTR46
I didn't think about the heat from the selinoid, I'm sure it will be hotter in the summer is this a hazard?
So I need to look for a vent that is a roll over vent

 

Your tank has two 2" NPT openings. One is used fpr the refueling pump while the other is plugged. There is no rollover vent fitting. I believe the reason the fuel is not flowing well when the solenoid is opened is due to a lack of venting. Gas flowing out must be replaced by air flowing in. I would consider installing a rollover vent. Amazon has one I used.
I used this ball valve that has wiring for indicator lights for open/closed. I used red for open and green for closed using a DPDT toggle switch.
https://ussolid.com/u-s-solid-motori...ire-setup.html

The problem with solenoids is they pull full amperage when opened and the coil gets very hot and life is shortened due to heat.

 

Thanks again for your help!
I did try and search this before I posted but nothing came up. Funny thing though after I posted this at the bottom similar posts showed up 😒

 

Water is heavier than diesel, so water is what falls to the bottom of the tank and agglomerates there.

Dirt and contaminants that are heavier than diesel will also sink to the bottom of the tank, joining the water.

When you draw from the 3/8" drain port of your auxiliary tank, you are guaranteeing that any contamination that is in your auxiliary tank, will be first in line to get into your main tank, and the CP4.2 fuel pump in your 2015 6.7L.

That's why installations of bed mounted auxiliary fuel tanks include a fuel pump mounted on top of the tank, that has a draw tube that stops 2 to 3 inches SHORT of the bottom of the tank, to keep from delivering the accumulated water and sediment that falls to the bottom of the tank.

Even if pristinely filtered fuel has always been put into your auxiliary tank since the day you picked it up brand new, your ATI TTR46, while DOT certified (which is a plus, not all transfer tanks are) is yet still a single wall tank.

This means that overnight condensation can cause beads of water vapor to condense and form on both outside and inside surfaces of the single wall sheet of thermally conductive aluminum. The beads of water condensation on the inside walls of the tank above the fuel line will rain down onto the fuel, and because water is heavier than diesel, will sink down to the bottom of your tank. Which is what you put into your main tank, and put through your CP4.2 fuel injection pump, when gravity feeding from the drain port of your auxiliary tank.

 

Thanks for the reply
If I install another water separator will that help?

 

Keeping the fuel tank full helps very much stopping the condensation from forming on the inside of the tank except on the tank ceiling, condensation can still form there. Biggest reason I draw the fuel from the top, my suction tube is 3/4" off the bottom and all fuel runs first thru a standard fuel filter on the suction side of pump and then thru a water separator filter on discharge side of pump.

 

So I'm still.waiting on the tank vent
I noticed when I remove the cap from the aux tank it doesn't have a suction however when I remove the cap on the truck tank it has pressure built up
Is this normal