Fuel Tank Relocation (and new Rear Bumper design)

[pfeenstra]

I just finished roughing everything in. I franken-fillered it with the stock rubber and steel fill tubes cut up and hose clamped together. It doesn't look to crazy lol. I was planning on plumbing the fill vent into the Ford breather on top of the tank. How did you run your vent that you think it is causing a leak out the cap?

There are a bunch of different problems with the way that I plumbed in the tank, I dropped it out to do it right.

• The Ford vent doesn't vent the tank fast enough to fill the tank with gas, gas keeps building up in the filler and runs back out onto the ground.
• Plumbing the Ford vent to the filler vent doesn't vent the tank when it gets hot, I have had gas sprayed on my hand when I opened the cap because it was pressurized.
• When the vehicle is at a 45 or more angle, gas will run up to the filler cap and eventually go through. This is a non-issue if you're not going rock climbing or steep hills.

Now I have to drop the tank out, make sure there's no gas/vapors left in it, and find someone to weld on the thin sheet metal

 

[phattyduck]

Now I have to drop the tank out, make sure there's no gas/vapors left in it, and find someone to weld on the thin sheet metal

Fill with water, then dump out the water, then dry it out.

-Charlie

 

[D'arce]

There are a bunch of different problems with the way that I plumbed in the tank, I dropped it out to do it right.

• The Ford vent doesn't vent the tank fast enough to fill the tank with gas, gas keeps building up in the filler and runs back out onto the ground.
• Plumbing the Ford vent to the filler vent doesn't vent the tank when it gets hot, I have had gas sprayed on my hand when I opened the cap because it was pressurized.
• When the vehicle is at a 45 or more angle, gas will run up to the filler cap and eventually go through. This is a non-issue if you're not going rock climbing or steep hills.

Now I have to drop the tank out, make sure there's no gas/vapors left in it, and find someone to weld on the thin sheet metal

I don't have the part number off hand but the breather I have on my tank is wide open until the breather goes upside down or fuel hits it and it floats up and closes. Could you have a bad breather (stuck closed)?

I welded on the Toyota fill tube adapter which has a little spring loaded door on it. I noticed before I added it that the Ford tank was just a hose adapter, no gate valve. Ford must have one on their trucks somewhere.

 

[D'arce]

There are a bunch of different problems with the way that I plumbed in the tank, I dropped it out to do it right.

• The Ford vent doesn't vent the tank fast enough to fill the tank with gas, gas keeps building up in the filler and runs back out onto the ground.
• Plumbing the Ford vent to the filler vent doesn't vent the tank when it gets hot, I have had gas sprayed on my hand when I opened the cap because it was pressurized.
• When the vehicle is at a 45 or more angle, gas will run up to the filler cap and eventually go through. This is a non-issue if you're not going rock climbing or steep hills.

Now I have to drop the tank out, make sure there's no gas/vapors left in it, and find someone to weld on the thin sheet metal

I see now that I was about to do what you had maybe already done. I was planning on using the evap vent on top of the tank as the fill vent. I can see that won't work as hardly any air moves through the valve. There must be a 1/2" barbed fitting that has threads on one end to attach to the tank...without welding. Something like thisRaceFlux 1/2" Hose Barb to O-Ring Adapter Fitting I just finished hanging my tank so I will have to take it down and add the 1/2" line. I ditched the evap so maybe I'll run the vent on top into the fill vent through a t?

 

[pfeenstra]

I see now that I was about to do what you had maybe already done. I was planning on using the evap vent on top of the tank as the fill vent. I can see that won't work as hardly any air moves through the valve. There must be a 1/2" barbed fitting that has threads on one end to attach to the tank...without welding. Something like thisRaceFlux 1/2" Hose Barb to O-Ring Adapter Fitting I just finished hanging my tank so I will have to take it down and add the 1/2" line. I ditched the evap so maybe I'll run the vent on top into the fill vent through a t?

That's exactly my problem. The gas cap doesn't vent nicely like I thought it would either. Now I'm going to plumb it into the same vent as my front tank and hope it doesn't trip any CELs. If I wasn't worried about passing CA smog I might buy one of these
Amazon.com: Dorman 924-284 Front Axle Vent for Select Lexus / Toyota Models: Automotive
and plumb it somewhere high and dry similar to the rear diff breather extension.

No welding is definitely better... how would you secure that Hose Barb on the inside of the tank so that it seals though?

 

[D'arce]

No welding is definitely better... how would you secure that Hose Barb on the inside of the tank so that it seals though?

There would have to be a matching female threaded piece on the inside of the tank.
I found some 90 degree threaded fittings that may work better. That AN fitting I linked to had o-rings but may not be available to me locally. I'm headed to Lowes to see if there is a similar brass fitting that can be slathered in fuel tank repair sealant. As I write this I remembered Car-Quest makes hydraulic hoses, they may have the AN fittings...

Oddly enough Ford uses a small vent hose inside of the fill tube to vent their tanks, at least on the Bronco. I read some threads of people complaining about miserably slow fill times so apparently even they didn't get it right.

 

[D'arce]

Spoke with Chris at Tanks, Inc. They have a rollover check valve that can be added to the end of the evap line. He suggested gutting the evap diaphragm for max flow and it should fill fine.
Roll over tank vent

I saw they also have this...
Bulkhead barb fitting

 

[Kirk D]

There would have to be a matching female threaded piece on the inside of the tank.
I found some 90 degree threaded fittings that may work better. That AN fitting I linked to had o-rings but may not be available to me locally. I'm headed to Lowes to see if there is a similar brass fitting that can be slathered in fuel tank repair sealant. As I write this I remembered Car-Quest makes hydraulic hoses, they may have the AN fittings...

Oddly enough Ford uses a small vent hose inside of the fill tube to vent their tanks, at least on the Bronco. I read some threads of people complaining about miserably slow fill times so apparently even they didn't get it right.

To solve the filler vent or vapor recovery problem I used this.

8AN Fuel Cell Bulkhead Fitting Adapter Aluminum AN8 Locking Nut 8 AN Male Flare Thread with Teflon Washer Amazon.com: 8AN Fuel Cell Bulkhead Fitting Adapter Aluminum AN8 Locking Nut 8 AN Male Flare Thread with Teflon Washer: Automotive

-8 an is 1/2 inch and I grabbed a 90° thread to barb to put on it. Simply drilled a hole in the tank on the highest point closest to the filler neck. Caught everything I could with a magnet and fished a strong one around in there after that. It’s higher than the top strap for the tank and significantly higher than the filler opening. Fed it back into the fillerneck up near the cap by teeing it into the factory vapor recovery line as high as possible. I also maintained and teed into the evap system because this is California.

My filler neck for both tanks is shown over in my build thread but if merging them isn’t an option a second factory one can be used in the fender well and the filler vent line thing still works. Did it on a friends.

If I suck the tank dry it fills right up to 20 gal and shuts off with the trigger just like it should.
Only tank over pressure issue I’ve had has been heat buildup related due to return line temperatures (I think) and the addition of a skid plate retaining heat under there. Happened once when I was forced to sit with the automatic in 2nd climbing the mountain by tourists not understanding the reason for turnouts.

 

[octanejunkie]

Finally ordered this kit, now looking to match it with a tank and wonder if I should pick up one with a pump and a sending unit for $249 versus a bear tank for 120

 

[2TH4IST]

I'm not 100% sure, but I think a few people who did the whole f150 tank (pump) found out it doesn't put out enough psi at higher rpm's for the 4runner. IIRC it's in this thread somewhere. Simple fix will be install an upgraded pump.

There is another member who males a gauge adapter to fit the oem toyota sending unit to the f150 pump housing if you go that route.

Just remember the stock f150 pump doesn't have a "sump" so you will have fuelling issues at steep angles.

I know it increases the difficulty quite a bit, but I highly suggest grafting the 4runners tank stuff into the f150 tank. That is what I did, and I have zero fill up issues or gauge issues. Heck I have had zero issues since I installed the f150 tank.

My pics of what I did are in this thread.

 

[octanejunkie]

I'm not 100% sure, but I think a few people who did the whole f150 tank (pump) found out it doesn't put out enough psi at higher rpm's for the 4runner. IIRC it's in this thread somewhere. Simple fix will be install an upgraded pump.

There is another member who males a gauge adapter to fit the oem toyota sending unit to the f150 pump housing if you go that route.

Just remember the stock f150 pump doesn't have a "sump" so you will have fuelling issues at steep angles.

I know it increases the difficulty quite a bit, but I highly suggest grafting the 4runners tank stuff into the f150 tank. That is what I did, and I have zero fill up issues or gauge issues. Heck I have had zero issues since I installed the f150 tank.

My pics of what I did are in this thread.

I might keep the stock tank as is, initially, and use the F150 tank as an aux tank to simply refill the main tank to extend range.

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[D'arce]

Just remember the stock f150 pump doesn't have a "sump" so you will have fueling issues at steep angles.

I was thinking about this the last time I had my tank down. It kinda looks like the Ford pump has a small mini tank holding the pump (the big fat white housing)...could this act like a small reserve to mitigate this fueling issue when at angles?

 

[Bad Luck]

I was thinking about this the last time I had my tank down. It kinda looks like the Ford pump has a small mini tank holding the pump (the big fat white housing)...could this act like a small reserve to mitigate this fueling issue when at angles?

That is what acts as the sump for the f150 pump. If you adapt a Toyota fuel sender assembly over then you will need to transfer/fabricate a sump for the tank.

 

[sleepydad]

I might keep the stock tank as is, initially, and use the F150 tank as an aux tank to simply refill the main tank to extend range.

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oh come on the reason for moving the tank is so you can put in a sweet 4 link setup.

 

[octanejunkie]

Baby steps, brother, baby steps

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[D'arce]

That is what acts as the sump for the f150 pump. If you adapt a Toyota fuel sender assembly over then you will need to transfer/fabricate a sump for the tank.

Cool thats good news since I kept the Ford pump and just swapped over the level sender.

 

[octanejunkie]

I'm looking to find a way to transfer from aux tank to main tank via external (or internal) electric fuel pump.

I might do an external hose manually into the full next, or I might intercept the factory fill tube with a Y fitting. I would look to do similar with the vent (fill vent and tank vent)

Anyone do this successfully?

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[clearock]

I'm looking to find a way to transfer from aux tank to main tank via external (or internal) electric fuel pump.

I might do an external hose manually into the full next, or I might intercept the factory fill tube with a Y fitting. I would look to do similar with the vent (fill vent and tank vent)

Anyone do this successfully?

Sent from my Pixel 4 XL using Tapatalk

I know uve read up on all the f150 tank shitss etc.

IMO after looking into many many options, filling from one tank to another seems like a waste of time with much better options. On my current build I am almost at the point of building custom tank/s and if I go with 2 I am leaning towards designing something with one external pump and a switch to select which tank will b being drained. If u have to fill from one tank to another seems like ur better off carrying gas cans....If ur going to use the OEM tank and F150 the dual system find the fords hasn't let me down yet and u get to use the OEM fuel gauge to check levels in both when u switch the tank parts to toyota.

 

[Bad Luck]

I'm looking to find a way to transfer from aux tank to main tank via external (or internal) electric fuel pump.

I might do an external hose manually into the full next, or I might intercept the factory fill tube with a Y fitting. I would look to do similar with the vent (fill vent and tank vent)

Anyone do this successfully?

Sent from my Pixel 4 XL using Tapatalk

Have you read through Dirtco's aux fuel tank thread yet? Auxiliary Fuel Tank
JohnMC has a write up as well: Auxiliary tank install on 99 4Runner

 

[octanejunkie]

Have you read through Dirtco's aux fuel tank thread yet? Auxiliary Fuel Tank
JohnMC has a write up as well: Auxiliary tank install on 99 4Runner

I probably did back in 2019, but I lost all my bookmarks during the Great Pandemic and have to find everything that I had saved all over again LOL

Thanks for those links, Baddy

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