F150 tank as aux tank

[Hopeless Diamond]

So, taking a closer look at adding the F150 tank as a way to carry extra fuel instead of the 2 Jerry cans I have hanging off the back end on the tire carrier. It'll give me 18 gallons instead of the 10, it will only weigh a little bit more and it'll put that weight lower down and not hanging out so far back. Having had the joy of refueling from Jerry cans in the Arctic, I think an on-board, even mildly integrated auxiliary tank would be better.

I think mounting the tank is relatively easy now because of the great work of #eimkeith and the mounting hardware he's designed and sells. Now it's more of question of the fiddly parts, filling, transferring, etc.

How many have done this as an Aux tank? I'm not looking to get too elaborate with fitting a dual tank switch and running directly from it. I'm thinking of some sort of system of transferring to the main tank as it runs down. Simple toggle switch to turn on/off the pump manually.

I've read the threads here from eimkeith and others about how his brackets evolved but most of the info evolved to replace the existing tank so a lot of the hoses/lines are just reused and then figuring out how to make the fuel gauge work. As a secondary Aux tank you have to set it up with it's own system for filling, venting, and then of course how to get it from 1 tank to the other.

I think I have seen where people have just come up with a filler and had it in the wheel well. I assume they just tied the tank vents together and went from there. Not sure how the filler neck would survive in the wheel well, but I haven't really looked into how it would sit or if there's a way to give it some protection. Wouldn't be too adverse to cutting in another filler opening in the fender, but it would need to be a pretty clean way of doing it.

I assume if the tanks are all plumbed together correctly and gas caps, etc are right, the EVAP system will still think its working ok. Yeah more of a load on the charcoal, but mines on the way out anyway.

Then transferring between tanks. Some sort of Y fitting (like a universal vent fitting?) in the stock filler hose and just pump into that? The Ford EFI pump may take forever to transfer the fuel though, maybe find a higher volume pump (think I've seen some 550lph pumps, or go external with a carb type low pressure/high volume pump). Would pumping from the aux tank into the other cause a vacuum which would mean you probably would have to open the filler or would the vent system equalize it enough between the 2? Would love to be able to do this on the fly.

Probably real simple solutions, and many smart people here have already gone through this. Just looking to gain some of your knowledge and experiences.

Thx,
JR

 

[2TH4IST]

That is a lot of questions lol, I'll try to help as I just did the f150 tank a few weeks ago but ditched the oem tank.

First 18 gallons of gas weigh a fricken ton! Ok more like 110 pounds, that is a lot of weight so springs will need to be changed, on top of some type of rear protection (skid and plate bumper). I'm guessing you have a plate rear bumper, if not then you loose most if not all the crash brackets when you put the tank in.

As for hooking it all up, I'd suggest running it as a separate tank. Thus all you would need is a filler neck, a vent (don't hook that up to the stock one), and use the f150 pump/sender and a separate gauge. And plumb the ford tank feed into the oem return line, might need a check valve to prevent the oem return from filling up the f150 tank.

Problem becomes when you pump in the fuel, the oem tank will get pressurized so maybe a solenoid vent? One that only vents when power is applied to the f150 pump. Manually shut the system off when your gauge reads full.

From what I have seen it's a PITA to run it as a dual feed tank. I drew a pic, don't know if it would work or not so use at your own risk.

 

[Hopeless Diamond]

Yeah, it will weigh a bunch, bit considering the weight of the 2 x 5gal jerry cans and the 2 can holder (4XInnovations - holy crap that thing is heavy), it's almost a wash and moves it forward and down.

Didn't think about plumbing it into the return line, that's probably a lot cleaner. Why not tie into the stock vent? If you keep both tanks are connected through the vent and maintain integrity at the filler and gas cap, would the EVAP system just see it all the same? If the 2 tanks vents were tied together, wouldn't the pressure of the tank being filled offset the vacuum the other tank (check valves may not allow this)

 

[2TH4IST]

Hmm if tying the 2 filler vents, those are primarily used to vent during fill ups. The hose goes from the top of the oem pump bracket to the top of the filler neck, it's what helps stop the gas pump when the tank is full. But it may work to equalize the 2 tanks during fuel exchanges. The evap is only to keep tank pressure in check during vehicle operation, there is a check valve on the oem tank that will somewhat prevent the evap canister become fuel soaked if you keep clicking the gas pump.

Most of the transfer tanks I see are on semi trucks, which just vent to the atmosphere and pressure differences just vent off. Back in the day when I had a 1jz swapped cressida, I vented the tank into a charcoal canister then to atmosphere, but I was running a standalone ecm.

Or a even simpler solution, hook the ford pump/sender to a manual switch and run the feed hose into the filler neck of the oem tank. Don't tie anything into the oem system. It would be like pumping gas from a Jerry can. You would need to figure out the filler neck.

 

[Hopeless Diamond]

I like your idea of dumping it into the return line, using check valves on either side of the tee. Don't have to mess with the filler tube at all.

Transferring fuel will create a pressure imbalance, so either they need a way to relieve, equalize that, or you would have to open the gas caps of both tanks to do it, which means stopping and waiting while the low volume pump chugs a long. (maybe a dumb question and never really thought about it before, do gas caps allow outside air in as the tank empties, or how does it not create a vacuum as the gas is pumped out?)

Long haul diesel PU guys do something similar with a bed tank, in fact that's on my ever growing to do list of vehicle projects for my truck. Gonna dig around and see how they deal with vents, etc

 

[Doc2012]

So, taking a closer look at adding the F150 tank as a way to carry extra fuel instead of the 2 Jerry cans I have hanging off the back end on the tire carrier. It'll give me 18 gallons instead of the 10, it will only weigh a little bit more and it'll put that weight lower down and not hanging out so far back. Having had the joy of refueling from Jerry cans in the Arctic, I think an on-board, even mildly integrated auxiliary tank would be better.

I think mounting the tank is relatively easy now because of the great work of #eimkeith and the mounting hardware he's designed and sells. Now it's more of question of the fiddly parts, filling, transferring, etc.

How many have done this as an Aux tank? I'm not looking to get too elaborate with fitting a dual tank switch and running directly from it. I'm thinking of some sort of system of transferring to the main tank as it runs down. Simple toggle switch to turn on/off the pump manually.

I've read the threads here from eimkeith and others about how his brackets evolved but most of the info evolved to replace the existing tank so a lot of the hoses/lines are just reused and then figuring out how to make the fuel gauge work. As a secondary Aux tank you have to set it up with it's own system for filling, venting, and then of course how to get it from 1 tank to the other.

I think I have seen where people have just come up with a filler and had it in the wheel well. I assume they just tied the tank vents together and went from there. Not sure how the filler neck would survive in the wheel well, but I haven't really looked into how it would sit or if there's a way to give it some protection. Wouldn't be too adverse to cutting in another filler opening in the fender, but it would need to be a pretty clean way of doing it.

I assume if the tanks are all plumbed together correctly and gas caps, etc are right, the EVAP system will still think its working ok. Yeah more of a load on the charcoal, but mines on the way out anyway.

Then transferring between tanks. Some sort of Y fitting (like a universal vent fitting?) in the stock filler hose and just pump into that? The Ford EFI pump may take forever to transfer the fuel though, maybe find a higher volume pump (think I've seen some 550lph pumps, or go external with a carb type low pressure/high volume pump). Would pumping from the aux tank into the other cause a vacuum which would mean you probably would have to open the filler or would the vent system equalize it enough between the 2? Would love to be able to do this on the fly.

Probably real simple solutions, and many smart people here have already gone through this. Just looking to gain some of your knowledge and experiences.

Thx,
JR

Why only 10?

Stock tank is 18.5; so you’re actually losing .5 gal. (Just because you’re only putting 10 into your tank doesn’t mean that it’s actually 10.)

Unless, of course; you went with a bronco tank.

The benefit of a F150 tank is that it’s behind the axle and tucked up; which equals belly clearance, and no ‘Taco Lean.’ No one, to my knowledge, had made it strictly and ‘auxiliary tank.’

IOT make it a ‘true’ aux tank: you’d have to do a lot of work. Not sure the evap system would like two tanks.

However, I suppose it can be done.

Just get a stock F150 pump, and figure out a way to plumb it into the stock tank.

Filling might be a little trickier.


Sent from my iPhone using Tapatalk

 

[2TH4IST]

Hmm, maybe gut the f150 pump hanger and install a high flow pump, should be easy. The issue is venting both tanks while driving. If the evap sees a pressure drop it will throw a check engine light. Either a small leak or large leak. No gas caps don't vent, unless they are broken.

As for the check valves, they would need to be a low psi. I do not know what the return psi is, if any. Feed line is 5/16" return is 1/4".

Tricking the evap sensors to not throw a code will be the tricky part unless you only fill up when engine is off.

As the gas heats up it creates pressure, expansion to be correct, which the evap system purges.

Maybe a check valve in the evap line to prevent pressure bleed off?

Let me kick this idea around a bit and I'll post up some ideas. This is interesting me a bit lol.

 

[Bad Luck]

So, taking a closer look at adding the F150 tank as a way to carry extra fuel instead of the 2 Jerry cans I have hanging off the back end on the tire carrier. It'll give me 18 gallons instead of the 10, it will only weigh a little bit more and it'll put that weight lower down and not hanging out so far back. Having had the joy of refueling from Jerry cans in the Arctic, I think an on-board, even mildly integrated auxiliary tank would be better.

Probably real simple solutions, and many smart people here have already gone through this. Just looking to gain some of your knowledge and experiences.

Thx,
JR

Dirtco did an auxiliary tank setup and write up. His is a little different as he didn't use an f150 tank but the concept is the same and should transfer over. Here's a link to his write-up: Auxiliary Fuel Tank Been a while since I read through it, but I think he encountered a couple design problems and fixed them later in the thread.

 

[clearock]

All of this has been gone over in detail if u search a little. Ur making it harder then it needs to be... no need to transfer fuel, the evap system doesn't care if u tie 2 tanks to 1, u can have on the fly tank switching by using the ford dual tank switch... ur fuel gauge with work/switch between tanks. been running this setup a while now

 

[Hopeless Diamond]

All of this has been gone over in detail if u search a little. Ur making it harder then it needs to be... no need to transfer fuel, the evap system doesn't care if u tie 2 tanks to 1, u can have on the fly tank switching by using the ford dual tank switch... ur fuel gauge with work/switch between tanks. been running this setup a while now

Am coming to that conclusion on the EVAP, as long as the entire system maintains vacuum, it could care less.

Read through Dirtco's thread and your input on it, lots of good info. Being able to switch between tanks would be nice, and I may end up going that route. How did you deal with the Ford sending unit (doesn't the Ford read backwards?) in the new tank or did you graft in the Toyota stuff like in midcoma's thread you referenced? In my mind I was just thinking of doing a simple transfer system from one to the other through the filler tube. Dirtco ran into some of the problems with that "simple" way of doing things and it may be more work and complexity than doing the dual tank set up.

I got connected with the technical guy at Long Range America, US branch of the Australian company that makes complete systems for all kinds of vehicles, including 4Runners. Their systems just do the transfer. They make a cool dual throat filler tube, just point the nozzle down one throat or the other, has both vent tubes and a tube for the fuel transfer. While probably not as much $$ as the factory Landcruiser set up, probably still not cheap, and not sure if they will sell components only. The system they have goes for ~$2k and is 29 gallons which is bigger than I want to go and probably hangs down lower than I'd like. I'll see what they say...

 

[clearock]

I went with all Toyota on the ford tank, that way I can carry 1 pump as an extra and so the gauge would not read backwards, and 2 keep it all Toyota (which can b corrected, search and u should find said).

29gals is a lot of fuel to be hanging out at one point and the idea of a low hanging tank and wheeling doesn't sound good. 2k is a lot to pay 4 something that u can DIY and IMO have a much better system then using a transfer system. I read up a lot on the dual tank idea and look at the company ur talking about and just didn't like the whole transfer thing so that why i decided to try the ford system. Don't quote me but as i recall when i was reading up on the twin tank filler there was an issue, fuel going it to the wrg tank sometimes or something like that (this may not have been the issue but there was a problem that made me nicks the idea), so i decided not 2 make a dual filler neck and went with 2 fill points.

 

[Hopeless Diamond]

Still noodling through the direction I want to go. I talked to the guy at LRA, they don't officially have a set up for US 3rd gens. One of their dealers in Texas did an install based on the AUS Surf set up they have. They're trying to develop a package from that install. Hard to say how much interest there would be here in the US for an expensive add on for 20+ year old vehicle platform.

There are different types of filler setups, the 4th Gen one basically Tees the two tanks together I think. The twin filler they use for the Surf has 2 channels that you slip the nozzle into based on which tank you want to fill, but they are still combined at the cap. I have friends with this set up on their Mitsubishi Pajero and have had no problems. It set up for transferring between tanks, but that inlet could be capped if you went the dual tank route (now the way I am leaning...). If only I could get them to sell me that alone (without breaking the bank)

 

[phattyduck]

It looks like the Long Range option is for a diesel, which has a slightly different fill neck. Might be a reasonable place to start, but it will have to be modified.

-Charlie