I recently purchased a RDS aux. tank/toolbox combo. I'm running it as a gravity fed system right now. Some people have told me that i would have problems with the guage reading full all the time. So I want to add a pump with a switch in the cab, but i need some way of having it return back to the aux. tank if i forget to turn the switch off, this way it does not overfill. If anyone can give me some instruction on this it would be greatly appreciated.

Thank you

 

on a gravity feed you main tank will read full untill the aux tank runs dry, then your gauge in the truck will start to read then you know you our on the main tank none left in the aux tank thats the way most guys on here have there truck set up, just did mine today or finished it today works just fine

 

I have it that way now, but when it sits, it start draining fuel through the rollover valves.

 

you talking about the two vents at the end of the tanks? if so it shouldent be doing that, they should be in only no out,

 

Thats what i figured.I just ran fuel line from them up to the inside of the bed rails.

 

you can tie the two togeather should be no problem your cap on your main tank is a air in only no fuel or air out. If it needs to draw air in the main tank cap will work and if it needs to expand the vent on you aux tank should do the venting. Lets just use this as an example if you did the vent mod you could fill the tank up to the fill neck that means you would run fuel out the two small vents, that shouldent happen they should be in only, plug them. but see if someone will chine in but I dont think you will have a problem pluging them there for Gas trucks some of the Diesel tanks dident have them on there guess it was the luck of the draw who got what

 

I know of someone with an aux tank. He has a switch to turn the pump on and off. One day while cruising down the hwy he looked out his driver side mirror to see his fuel coming out his filler cap. He forgot to turn it off. He now uses a little timer inside the cab so that doesn't happen again. That's like throwing money out the window, plus the MTO wouldn't like it very much.

 

No doubt, LOL. I have heard that you can use some kind of selector switch that has a return on it. But I have no idea where to start.

 

Richard I have a ATTA pluming kit for a 05 Dodge Diesel pump, gauge, switch,Fuel lines whole kit if you have a pick up tube in your Aux fuel tank and a return and roll over valve and sending unit, I will sell you the kit for $150.00 then you can switch from tank to tank. Only thing that is missing out of the kit is the sending unit had to use it in my tank to fill the hole. Only reason why I have an ATTA tank is because I won it. not that it is not a nice tank but to much money for me, Reason why I did a gravity feed is because of my fuel sys I have on my truck GDP too much of a pain to plumb up the right way. just need some time to figure it out sure it could be done.

 

Ya, i saw that kit. I was hoping just to pump into the factory tank and not switch between tanks. Thanks for the offer though.

 

If you read my recent post about doing this, there's more there. But here's what you need: it is sold by a lot of guys who use a second tank for SVO - straight vegetable oil. Try this on Google: Pollak Actuator Products Division. Item #42-300, Light truck 6-port motor-driven valve. This runs about $70 from the places I have seen on the net. "Motorized fuel tank selector valves (Diesel or Gas)". Look for the kit with all the parts - the switch is nice to have. These valves are for the return lines and the supply lines, plus they shut on/off each fuel pump.

 

Only plug the two vents on top of fuel tank if your truck has another way to vent such as through your auxillary tank. The auxillary tank should be vented anyhow. The spring in the stock fuel tank cap is too strong for sucking air in and could lead to an early death of your stock lift pump.

I only interjected this because I didn't want other guys crawling under there trucks plugging the vents on top of their fuel tanks.

 

Ture my bad should of said that little more clear need aux tank to vent to plug the two on the main tank, I just used my roll over vent as a vent for in and out air, but I dont have my two small vents pluged and there are no leaks so far, Knock on wood

 

another thing you might want to add if you have a shut off valve from the Aux tank then with the two vents pluged and the valve shut no vent again but I dont have a shut off valve

 

I have a L-shaped tank that was given to me and want to install. Since I have the fuel tank vent mod install, I was thinking I could connect to the OEM vent tube to the aux tank with filters and on/off vavle. Would this be ok??

Of course I would install a filter for gravity flow and turn off vavle for safety.