Gasoline Transfer Tank.

I believe you are correct on not being allowed to gravity flow into the main tank. One of the aftermarket tank vendors shared this with me.

This vendor also said it was illegal to carry more than 15 gallons of GASOLINE in the bed, although I can buy 90-100 gallon tanks designed for gasoline in the bed. Anyone know if this alleged legal limit on volume is real?

The law is you cannot have a gasoline aux tank that gravity feeds into another gas tank (ie: feeding into the truck's main factory gas tank). It's legal to do this with diesel, NOT with gasoline.

I am SERIOUSLY studying this mod right now for my Tundra. Replacing the stock tank is the best solution, but my manager (DW) will never approve $1,800 for a 46 gallon replacement tank. I need a ~ 20 gallon in-bed transfer tank and am actively shopping now.

Aside from the actual tank and installation, I am wondering about the logistics (and legalities) of stopping on the side of the road and throwing a hose out of the bed and into the factory fill neck to transfer the fuel.

For those of you that have this and do it, have you ever been hasseled about doing it? Ever been asked to leave a location?

ALSO, does anyone know a place to get CREDIBLE information on the legal restrictions around this project?

Thanks

I have noticed when driving a long distance and stopping for gas when I turn the gas cap it will release pressure from the tank and quite a lot by the sound.
this is a 2005 hyundai elantra car.

this is after driving like 2-3 hrs.

Denny & Jami wrote:

IDoMyOwnStunts wrote:

Denny & Jami wrote:
I've been using a older version of this tank sense 95 (third truck) Tank. I pump it out of the tank with a Holley roitory vane pump and isolate the tank with a solenoid valve, I have a fitting silver soldered into to fill pipe so I can transfer going down the road without stopping. I used to vent it into the trucks vapor system but I would get a open gas cap light so now with this truck so I just have a filter on the vent hose, the tank has a rollover valve built into the vent outlet.

The truck doesn't pressurize the tank it pulls a vacuum on it every so often to check the gas cap. When you install a aux tank and when both the aux tank and main tank gets low it takes to long to pull the slight vaccum so you get the light, the rest of the time the tank vents through the recovery canister to open air. You just have to isolate the tank when not transferring fuel.

Denny

My bad. Some manufacturers do pressurize their tanks for a check, though.

Yes they did at first but the tank under pressure was not a great idea if you happened to remove the cap at the wrong time. Better sucking in than blowing out :B

Denny

My Volt still does. However, it has a switch you have to press on the door before fueling so it can vent the pressure off. That design is to preserve the fuel, though, since a tank can last for several months.

I did the same as Denny on my 2012 Ford. I have a veton normally closed fuel shut off valve inline with the fuel pump.

So it is closed when the pump is off and open for pumping since it is in the same electrical circuit as the pump.

IDoMyOwnStunts wrote:

Denny & Jami wrote:
I've been using a older version of this tank sense 95 (third truck) Tank. I pump it out of the tank with a Holley roitory vane pump and isolate the tank with a solenoid valve, I have a fitting silver soldered into to fill pipe so I can transfer going down the road without stopping. I used to vent it into the trucks vapor system but I would get a open gas cap light so now with this truck so I just have a filter on the vent hose, the tank has a rollover valve built into the vent outlet.

The truck doesn't pressurize the tank it pulls a vacuum on it every so often to check the gas cap. When you install a aux tank and when both the aux tank and main tank gets low it takes to long to pull the slight vaccum so you get the light, the rest of the time the tank vents through the recovery canister to open air. You just have to isolate the tank when not transferring fuel.

Denny

My bad. Some manufacturers do pressurize their tanks for a check, though.

Yes they did at first but the tank under pressure was not a great idea if you happened to remove the cap at the wrong time. Better sucking in than blowing out :B

Denny

Denny & Jami wrote:
I've been using a older version of this tank sense 95 (third truck) Tank. I pump it out of the tank with a Holley roitory vane pump and isolate the tank with a solenoid valve, I have a fitting silver soldered into to fill pipe so I can transfer going down the road without stopping. I used to vent it into the trucks vapor system but I would get a open gas cap light so now with this truck so I just have a filter on the vent hose, the tank has a rollover valve built into the vent outlet.

The truck doesn't pressurize the tank it pulls a vacuum on it every so often to check the gas cap. When you install a aux tank and when both the aux tank and main tank gets low it takes to long to pull the slight vaccum so you get the light, the rest of the time the tank vents through the recovery canister to open air. You just have to isolate the tank when not transferring fuel.

Denny

My bad. Some manufacturers do pressurize their tanks for a check, though.

carl2591 wrote:
I was going to use an elec valve to control the fuel flow so when not flowing the valve would be shut off. This should allowing the system to perform its vacuum function and prevent the CEL right..

how often does the system do this vacuum to check for open fuel cap condition? it seems if you had a 1/4 or lower tank it would take longer to get a 25 gal tank to vacuum than one 1/4 full.

I would guess the system performs this test say at startup or after seeing the fuel level gauge go up maybe..?? I am not sure.

SO Denny you have a valve that closes after you allow fuel to flow and that prevents the CEL for open gas cap you are saying.??

Denny & Jami wrote:
I've been using a older version of this tank sense 95 (third truck) Tank. I pump it out of the tank with a Holley roitory vane pump and isolate the tank with a solenoid valve, I have a fitting silver soldered into to fill pipe so I can transfer going down the road without stopping. I used to vent it into the trucks vapor system but I would get a open gas cap light so now with this truck so I just have a filter on the vent hose, the tank has a rollover valve built into the vent outlet.

The truck doesn't pressurize the tank it pulls a vacuum on it every so often to check the gas cap. When you install a aux tank and when both the aux tank and main tank gets low it takes to long to pull the slight vaccum so you get the light, the rest of the time the tank vents through the recovery canister to open air. You just have to isolate the tank when not transferring fuel.

Denny

I use this time delay, this pump and this solenoid. Time delay, Pump, Solenoid.

I do not and will not gravity feed any fuel I pull it from the top of the tank, I have it wired off one of my uplifted switches and a small momentary rocker switch. The delay runs the pump and solenoid for 19 minutes then shuts off, in that time it will transfer 20 gal. And yes the solenoid stops any check light and it can only run when the ignition is on.

Denny

I put a 100 gallon tank of a freightliner in the bed of my 98 chevy 2500 350 engine bolted down to bed with the factory tank bracket put a little inline fuel pum hooked up to factory pick up tube and t–d it into truck fill conected vent on semi tank to vent hose on truck tank put a seperate fuel gauge in truck and pump on switch keyd to ignition worked great could go 850 miles before needing fuel inteat of about 150 i now have same tank mounted on back of a 2012 ram cab chassis but i gravity fed it with solonoid valve on a switch and tied vents together have a 152 fuel capacity now