Installing dual fuel fillers into one fuel tank

kcshoots

Member
I am busy installing the items between the chassis rails of my new expedition truck/camper in the making, and I want to install two fuel fillers, one each side, so there is less vehicle shell game and waiting to get to an open pump when at filling stations. I want the two fillers and their vent hoses to tee together near the tank, about four to six feet from the fuel filler. Yet I'm having difficulty finding a 2" fuel compatible tee or Y fitting. Any suggestions as to doing this and for resources to get the 2" fuel filler tee so I can add the second fuel filler? Thanks,
 

javajoe79

Fabricator
Any competent fab shop could set you up with a T or Y to your specs. Aluminum or stainless will be great. I would do a Y if you have space. I have seen a T in a similar setup cause some backup in the filler neck while filling. A large vent hose to the filler location will help with this though.
 

broncobowsher

Adventurer
Considering the filler neck is a lot more complex that a simple open tube, it would be better to put a second fitting on the fuel tank. Metal tank is a piece of cake, typically radiator shops do it. Plastic tanks you are looking to make a Y-fitting for the filler neck.

So what makes them complex? As fuel goes in, air comes out. But not just out, up to the filler nozzle. When the air coming out spits fuel out it hits the nozzle and trips the auto shut off. Get it wrong and as fuel goes in the air gargles coming out splashing up the filler neck and the nozzle auto shut off will be tripping all the time. Usually end up filling on the slowest fill speed and that often makes the auto shut off not work. Next thing you know you are overflowing the tank onto the ground. So while it sounds like an easy upgrade to do a dual sided fuller actually getting it to work right can be a challenge.

So long as you have good filler caps on both sides there really isn't a chance of it pouring out the other side as you fill it. Unless you remove both filler caps at once. But you are just asking for your own problems if you do that.
 

lugueto

Adventurer
A friend of mine did this mod once, for the exact same reason as you. The thing is with long fuel queues down here it shouldve helped a lot. There used to be a ridiculous "rule" where you could onlu fill using the pump on the same side as the filler cap. That is no longer an issue and it turned out to be more of a pain in the butt than worth it.

If this helps, he used a fuel filler made for a boat, it was vented to prevent any splashing or gargling as mentioned before. But was always in a weird angle and made for filling at the pump a little awkward, even though he installed it flush with the body, plus the cap was always super tight and wasn't easy to open.

If it were me, I wouldn't install it. I would reach for the other side with the hose and be done with it. If your vehicle is too tall and you can't go over, just park a little further forward and go round the back.
 
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kcshoots

Member
Pay attention to the venting so you're not filling one side and dumping fuel on the other.

Also locking if theft is a concern.

Lots of work for ??? gain. Truck stops I go to the hose reaches both sides.
All good points. Thanks for those. The current fuel filler is at the very back of the 21 foot long rig, so finding a space that is 20+ feet long to back into or pull straight into with the fuel filler on the correct side will increase odds of an available fuel lane from 50% to 100% assuming there is at least one available space.
 

kcshoots

Member
Considering the filler neck is a lot more complex that a simple open tube, it would be better to put a second fitting on the fuel tank. Metal tank is a piece of cake, typically radiator shops do it. Plastic tanks you are looking to make a Y-fitting for the filler neck.

So what makes them complex? As fuel goes in, air comes out. But not just out, up to the filler nozzle. When the air coming out spits fuel out it hits the nozzle and trips the auto shut off. Get it wrong and as fuel goes in the air gargles coming out splashing up the filler neck and the nozzle auto shut off will be tripping all the time. Usually end up filling on the slowest fill speed and that often makes the auto shut off not work. Next thing you know you are overflowing the tank onto the ground. So while it sounds like an easy upgrade to do a dual sided fuller actually getting it to work right can be a challenge.

So long as you have good filler caps on both sides there really isn't a chance of it pouring out the other side as you fill it. Unless you remove both filler caps at once. But you are just asking for your own problems if you do that.
Yes, agree. I am purchasing two new identical fuel fillers--cap, fill and vent tubes--one for each side, each about 18" above the top of fuel tank. Each fuel filler and vent will Y/tee together at just above the top of tank, so any fuel in either should fall into the tank and not rise up to the top of the other fuel filler.
 

billiebob

Well-known member
I am busy installing the items between the chassis rails of my new expedition truck/camper in the making, and I want to install two fuel fillers, one each side, so there is less vehicle shell game and waiting to get to an open pump when at filling stations. I want the two fillers and their vent hoses to tee together near the tank, about four to six feet from the fuel filler. Yet I'm having difficulty finding a 2" fuel compatible tee or Y fitting. Any suggestions as to doing this and for resources to get the 2" fuel filler tee so I can add the second fuel filler? Thanks,
What kind of vehicle? Regular trucks etc are really tightly regulated for fuel evaporative control and modification is not simple. If you have an old commercial truck the odds are much simpler but a regular pickup or SUV will be pretty complex.

If all you need is a t or y any commercial truck shop or marine supply should be able to help.
 

kcshoots

Member
I appreciate the helpful suggestions. I think I have a simple, reliable and safe system that will of course work as intended with the factory system, and save me and others time at the filling station with less musical cars to get the pump at the matching side. I'll share more with my build thread and videos to be helpful to others, which should get started soon.
 

javajoe79

Fabricator
You guys really should just not comment if you can’t contribute. This isn’t that complicated or difficult to achieve so if the guy wants to do it, so be it.
 
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