Dual tank install

Hey y'all. First post here but I am looking at getting a 82 dually that seems to have had both tanks installed at some point. The dash has the hole where the switch was, and the bed has fuel doors on both sides but just a tank on the drivers side. I haven't crawled under it to check out whats going on with it. But how simple is it in general to install the second tank and wire up the switch/plumbing. I haven't found any good resources on that side of things for a fuel system.

I would swap a suburban/blazer tank before I thought about adding a dual tank system. The switch valves are a pain in the ass.

Other than maintaining my dual tank system on my grandpas 79, all my trucks are going to be suburban/blazer tank swapped.

There are a bunch of dual tank threads on this site.

ferdaphoto said:

Hey y'all. First post here but I am looking at getting a 82 dually that seems to have had both tanks installed at some point. The dash has the hole where the switch was, and the bed has fuel doors on both sides but just a tank on the drivers side. I haven't crawled under it to check out whats going on with it. But how simple is it in general to install the second tank and wire up the switch/plumbing. I haven't found any good resources on that side of things for a fuel system.

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This is actually no big deal at all,especially if the tank valve and wiring are still there. The tank has 2 brackets 2 straps a sending unit a fill and vent neck and hose. It's all factory just put it all back in and hook it all back up. You aren't trying to invent the first wheel.You won't even have to make anything. Gather the missing parts and install them. In this world of videos for everything,watch some you tube videos on r&r fuel tank. Then watch done videos in pollack tank valve r&r.

I converted my 77 to the newer style efi tanks, valve and switch. It wasn't terrible. Took me a few weekends of a few hours each. I really do like having the dual tanks, and the redundancy in case one pump fails or something, as I take my truck out on trails alone quite often

You can buy new Pollack switching valves. No big deal. Putting a single tank in the rear is more of a pain in the ass. I've done both and then converted to EFI.

The wiring and switching valves changed over the years, so your best bet is to find a donor truck of a similar year and swap everything except the rubber hoses (those you should replace).

If they left everything in place there should be metal hard lines that cross under the cab between tanks, and probably a six port switching valve (it switches both supply and return lines). The rubber fuel filler hoses for the tanks are also a little different in some years, and relatively expensive new, so its best to find an original hose from a donor truck.

Wiring for the dash switch has a pigtail that goes through the firewall and then down the driver's side frame rail to the tanks. More wiring goes across the support to the passenger side tank. It's more complicated/convoluted than you would expect, so find a wiring diagram and follow it.

Make sure you know what year the bed is. The tank setup changed in 1979. It changes the filler necks and hoses, and the wrong ones won't work. LMC has all the parts you need except the Pollak valve, but you can find those. They're about a hundred bucks.

Hopefully your wiring is still in place. The switches are available on LMC. Just make sure you get the right year. If they left the wiring for the pollak valve you are in good shape. Put up two new tanks while you are there. It’s like an extra $100 each side. Also, Pro-tip; extend the fuel, vent and return lines between the sending unit and the steel line by about a foot get the clamps on them nice and perfect and let it curl up on top of the tank. Don’t try and get those three inch hose back on their. I have heard the fill hoses are a little hard to find.

The fill hoses are available, at least they are for my 1987. I just received my order. New filler necks and hoses.

The original valves are wired different than the current replacements. At least I am told that. I found an NOS one for my truck.