Factory Auxiliary Sub Tank Install (1 Viewer)

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Thanks for the write up Phil. I read it about 6 months ago and started gathering parts from various mud memebers. I pretty much follwed your write up all the way through. It was a bit of a pain to weld the gas filler neck with the nozzle restrictor on to the deisel dual filler neck. But i got it done and its all vacuum tight. It's nice to just flip the switch and add around 15 gallons to my main tank.
Thanks again
 
Almost ready to do this job and thinking - better to cut the neck on a full tank or empty?
 
Almost ready to do this job and thinking - better to cut the neck on a full tank or empty?
I've read gas tank full = less fumes. You could also disconnect the main and vent hoses going into the main tank if you want to be safer ish.

I'm in the same boat, just installed the four nutserts and bolted the tank up last night. Now, gotta pull it back out and start on the wiring.

Good luck with your project!
 
In areas with emissions testing it will fail the visual test.

Yeah its a non-starter here in CA.


No longer in California. My smog guy said that requirement was removed, and mine has passed at least once since the law change. He did say he didn't want to know about the dual tank though....
 
I had big plans for becoming a fueling station for everyone. As I struggled with a plan my wife of reason said I thought this aux tank was for you and what was wrong with the way you have done it in the past, I thought you liked things simple. Now if you run out of gas I cant help you and you can blame my wife.

I fab’d this y pipe thing’e to dump fuel into the main tank via the vent line by a transfer pump. Stupid simple and very effective way of transferring

View attachment 943099 View attachment 943100

Mounted an in-line pump for the transfer pump up high and out of the way along with a filter, all outside of the tank.

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Time to test….pump runs but I get nothing?? I realize my free pump is a gravity feed pump and will not work. Going with ‘its not the ***-up but the speedy recovery’ I started looking through my junk and come up with 3 Holley Blue pump from my X Trophy truck days. Re fab my mounts and install the Holley blue something I should of done from the beginning anyway being a faster, vane style self priming, and much better pump all around. Now I have transfer and super fast with Holley rated at 110gph.

View attachment 943102

I will be using a rear window defroster switch Im having relabeled with a reverse negative to give the factory look (not installed yet).

End results

View attachment 943103


Hey LandCruiserPhil,

Any way you could be persuaded to fab up another one of these y-pipe thingies? I'm working on installing my subtank and I'm having a hard time finding an easy solution to dump fuel from my subtank to the main.
 
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Some claim sub tank capacity at 13.5 gal. My tank must be special, first I filled my main then the sub tank.

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Yeah, that's close to typical for what I see when I fill our OEM subtank even though the 'spec' states 50 litre capacity. There may be a bit more capacity due to filler hoses etc. Presumably the spec is also conservative.

I know I can get around 14.5+ gallons into mine with the main filled and that's without 'over-clicking' while filling the sub.

cheers,
george.
 
Yeah, that's close to typical for what I see when I fill our OEM subtank even though the 'spec' states 50 litre capacity. There may be a bit more capacity due to filler hoses etc. Presumably the spec is also conservative.

I know I can get around 14.5+ gallons into mine with the main filled and that's without 'over-clicking' while filling the sub.

cheers,
george.

Good to hear Im not the only one.
The one part that could of made a difference in mine is when the tank was open I bent the breather tube in the tank up to the top:meh:
 
Thanks for the thread! Just curious what year model your dual filler neck was spec'd for?
 
Thanks for the thread! Just curious what year model your dual filler neck was spec'd for?

Not sure but do get the one where the outlets come out horizontal it will make hose hook much easier. Mine was new from Akella here on mud.
 
I like this thread - very simple and I will be doing the same set up shortly - right now my sub tank is in for cleaning. I'll be installing as soon as my new hoses and gaskets arrive.

My set up came with both dual filler neck and separate lower filler neck that joins the dual neck to the main tank. Since its out, I have no issue welding on it.

I like the idea of using a 3/8 inch hose barb to connect the hose from the pump. Can anyone think of a reason not just to weld in a bung into the lower neck (not vent line as per Phil) and use a brass npt hose barb? Do I need to worry about back filling from the main interfering with the fuel coming from the subtank transfer pump?
 
my tank paid itself in one trip not long ago i went to baja california all the way to cabo and back to wisconsin when light comes on between two tanks i can fill up 45 gal.
on one pump person who works on station was thinking something was wrong with the pump because i pumped 45 gal
 
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I did 500 miles round trip, DC to NYC and back. Thought I was running on fumes puling in to the cheap gas station in my town and only filled up ~36 gallons, at least a good 26 miles until empty. :D Definitely one of the most useful upgrades on my truck.
 
When you go this cheap Aux Fuel tank route, is there any reason you can't use the original fuel pump - float gauge assembly from the new tank and hook up a pump switch and aux fuel gauge?
I'm looking for some simple, reliable and cheap options (in that order) to extend my range for a Chile desert trip where there are not many gas stations. This seems to be the way to go and used tanks with the pump assembly are cheap and plentiful here.
 
@LandCruiserPhil @george_tlc

I have a 33 Gallon Aux tank I brought over from VZ. I like the fuel transfer solution with the Holley pump makes everything simple. I will be using the factory sub tank on and off switch (84560-60030) But I would like to integrate the OEM overhead console aux fuel level gauge. Wondering if this could be done with an aftermarket fuel level sender. Or wondering what other options are there to measure the fuel in the aux tank.

Have any pictures of how you piped in the y pipe you made?
 
@LandCruiserPhil @george_tlc

I have a 33 Gallon Aux tank I brought over from VZ. I like the fuel transfer solution with the Holley pump makes everything simple. I will be using the factory sub tank on and off switch (84560-60030) But I would like to integrate the OEM overhead console aux fuel level gauge. Wondering if this could be done with an aftermarket fuel level sender. Or wondering what other options are there to measure the fuel in the aux tank.

Have any pictures of how you piped in the y pipe you made?

I have had a couple aux tanks all set up on a similar transfer system and no fuel gauge. I keep 3 gals in my aux tank unless Im traveling then its full. When my full light comes on I get either 3 gals or 15 gals makes it very easy to know where you are at with fuel and keeps all your gas fresh. With that said lots of options for a fuel gauge if you want/need one. As for the switch there are 2 fuel switches available one on/off and one momentary. Both will work just one requires some other controls like a relay flow switch or the likes. Sorry no other pics than what has been posted in the past.

For the most part everything you asked about is possible with enough time and money. I like simple mainly because it end it increases reliability.
 
Even with an aux tank I still managed to run out of gas on this past Sunday 1.2 miles from a gas station:doh::bang:

Within 10 minutes a nice "prepared" guy in a beater Toyota Tercel stopped with a full 2 gal can. I dumped 1 gal followed by 39+ gals a mile down the road.
 

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