Triple tanks?

[thirdstreettito]

I was wondering, if you installed a suburban or blazer tank in a truck that already had dual saddle tanks, how would you choose which tank you would use? I would guess 2 factory type valves. One to switch between pass line and drivers line. Pass line to pass tank, drivers line with a second valve in it to switch between rear tank and drivers tank. Any help is appreciated. Thanks, Bradley

[veinbar]

Are you planning on robbing a bank? Don't worry, I won't tell

[thirdstreettito]

What do you mean? Because of the cost of filling 3 tanks? Or the distance I could go without filling the tanks(police chase)?

[SLEA]

It's just something not many have thought of i'm sure, you may be the only one. You may would have to put helper springs in the rear to keep it from sitting low in the rear when they all are full.

[Corts60]

The original owner I bought my short box from had three tanks. Two saddles and one 60 gallon tank mounted inthe bed. This tank had internal baffles to restrict free surface effect because it was so big.

Here is how he installed the system:

Both saddle tanks were left alone mechanically and electrically. Leave the dash switch alone. Install the third tank and run a fuel line from it to a filter/separater. From there run it to an aftermarket electric fuel pump (mounted whever you desire, mine was installed on the pass. side fender well). After the pump, run it to the filler neck of the passenger side tank. Done.

Here is how he ran the system during trips:

Fill up all three tanks and take off. Use the pass side tank first. While you are driving you will notice that it takes forever for the needle to move off of FULL because your third tank has been gravity feeding into that tank. You'll know when your third tank is low when your fuel gauge starts dropping. At this point kick on the fuel pump you installed to get the remainder of the fuel in the third tank to the pass side tank. Now when you can no longer add to your pass tank, your third tank is empty.

There are two things you can do next depending on what side your fill up for the third tank is.


If you install the fill for the 3rd tank on the driver side-

After the third tank is empty, switch to the driver side tank and when it is empty, switch to the pass. side and start finding a gas station. Now you can fill up both the third and driver side tanks without having to flip around.

There are two reasons for this. 1) You don't ever have to flip around again at the pump. 2) When your tank switch dies (and it will eventually), it automatically defaults to the pass. side tank. So you should always use your driver side tank first when you fill up.

Hope this helps.

[thirdstreettito]

My way seems a whole lot easier....

[Low87]

Seems like RandyP had this figured out. Or he had the idea to do it at one point anyways.

[78 Chevyrado]

I've kicked the thought around about the burban tank in a dual saddle pickup before. it's very interesting to me, especially when towing a 7k trailer on long distance trips. And I have HD 3/4 springs so it won't make mine sag when full.

My only hang up would be, would I be able to have the burban tanks AND a frame mounted HD towing hitch. I'd have to buy a kit, as the hitch I have now was custom made and is welded to the frame. So, anybody have a longbed 3/4 ton with a burban tank and a bolt on towing hitch?


Corts way isn't as simple to install as bradleys, but it sounds more reliable because the valves do fail. Though both ways will work fine other than that. I've had the extreme irritation of sitting on the side of the road out of gas with one tank slap full because the valve failed...lol

I'd love to have just an open tube from the third tank to the both saddle tanks, but I'd be worried about the gas cap leaking and I'd have to do something different with the vent tubes. The idea being there is fill all 3 tanks from one filler neck. The gas caps would worry me though. As long as the vents are a ways above the fuel level in the highest tank you'd be fine.

[thirdstreettito]

MY 84 had dual tanks, I didn't mind pulling away from the pump and turning around. But I usually didn't. It was diesel, so I got to use the big rig dual pump setup's. Makes life so much quicker. I could go over 800 highway miles before filling up. If I had installed the 40gal suburban tank like I waned to I could have gone 1800 miles. It would've been nice to fill up once every two months.

[Hulk Will Smash]

I'd thought about this for my dually as well. Man that gravity feed system just gives me a mental picture of a truck driving down the highway with fuel spewing from the filler... Must have actually worked, but it henks me out!

I dig the idea of two facotry selectors. Wonder how all those custom conversion places do the bed tank?
Posted via Mobile Device

[lrader99]

3 tanks? why not just run 4 and use the one behind the seat too...then you could go like 500 miles without stopping...

[thirdstreettito]

500 miles? That's like 5mpg.

[Corts60]

Originally Posted by thirdstreettito

500 miles? That's like 5mpg.

[Goldfinger]

I've looked into this. i'd suggest use all 3 tanks along with a sending unit designed for each tank. I then would add a switch system that would allow me to select one of three tank. this way you could maintain the mechanical pump and use all three tanks. on a long bed the hitch problem could be remedied by mounting it more towards the axle reduces the load on the axle and allowing the hitch to mount.

[Jay290]

Ok where do i get a diagram of the original setup from the factory. I've got an 83 with just the one saddle tank. The good side is it only costs $40 to fill up but about 200 miles is about all i get out of it.

[motornut]

not sure if it's what you want

[Goldfinger]

40 to fill up!! mine costs me over 130 at 3.70 a gallon

[Chevyman350]

I am going to do this and I am a cummins convert so diesel for me.

My plan is to use selector valves for WVO systems, they have to switch between two tanks.

Then have one forward to select between saddles and rear mount, and then one on the saddle line for selecting left and right.

And I am building a custom trailerhitch for my R30 to clear my 31 gal blazertank.

Have fun!

[ghettoluxury]

Originally Posted by thirdstreettito

500 miles? That's like 5mpg.

Some of us have big trucks with big motors!

[CowboyProtectionUnit]

Hey... LOVE the Thread!!!! SO wanna know how this turns out!!!

[wyattglock]

Originally Posted by thirdstreettito

500 miles? That's like 5mpg.

First off, this thread is great on several counts! Second, 5mpg might be a realistic number when you first roll out from the pump after getting that second mortgage. I would expect the mpg number to go up as the weight goes down.

[puppy]

I will share this. My 88 CC had this very thread topic "triple tanks" installed when I got it. 2 saddle tanks and a 100 gallon auxillary tank in the bed. The system did not work any longer (no surprise) and has been a PITA to try and get straightened out.

It was installed with the factory selector valve left in place and an external fuel pump and filter assembly feeding a second selector valve. All wired (bird nest) to a toggle switch replacing the factory selector switch. This was done so the engine could run off of any of the three tanks.

I do not know exactly how or why it ever came to this but I would not suggest doing it. I that isn't convincing enough, I would do as described above and just have the auxillary tank fill one of the saddle tanks thru a T placed in the filler neck vent tube manually controlled with a toggle switch.

I have almost gotten this mess cleaned up and back to stock.

Maybe this diagram will be of some assistance.

[rayfinseats]

I would just run an electric pump on tank 3.

[Dan1969]

This would be a Zombie Apocalypse Truck...