Rear tank swap

[Perkinator]

Hello everyone I’m new to the site found it after looking for info on my 1986 f150. My question is I have my 86 with duel tank but someone took off the rear tank and just plugged the lines. I have a 1980 f150 for parts with rear tank still on it. Is everything going to line up? Both carbed and both have 351 winsor.

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Black is 1986 f150 xlt lariat with 351 winsor short bed 4x4

2 tone is 1980 f150 custom with 351 winsor long bed 4x4

White 2006 f150 fx4 supercab with 5.4 shortbed

[Gary Lewis]

Welcome to the forum!  Glad you joined.  

You probably missed the email that asked you to go to the New Members Start Here folder, read the guidelines, and then introduce yourself by starting a new thread in that folder.  Don't worry, about 1/2 of the new members miss that email.  But we keep the guidelines in that folder for new members to see, so just want to ensure that you've had a chance to read them.  Yes?

As for the straps, they and the same.  But the tanks are probably different.  In 1980 the tanks had a small opening, but by '86 they'd changed to a large opening to allow the fuel pump to be installed there.  And the fittings are different as in 1980 they used rubber hose but in '86 they used nylon line.

So if you just want to use the straps it'll work.  But the tanks aren't a straight swap, although it can be done.

And by the way, here are your pics.  They are two large to be put on the site w/o choosing the "big" scaling option, which I've done.  But the bottom one needs to be rotated.  The issue is that forum software doesn't read the orientation info in the pics, so you have to do that in another app if you don't hold the phone/camera in the "normal" position.  Read about that on the Bullnose Forum/Forum FAQ's page.

[Perkinator]

Thank you for the info went back and posted to new member. And I was doing research last night and was afraid they wouldn’t match. Good news is have a 85 f250 with rear tank and a 5.0 for parts also I just trailered this one and took it home because it was prettier. The 85 rear tank off the 250 should fit correct? Also don’t know how to make a signature box is that something you type every post?

Also thanks for the info on posting pics

[Gary Lewis]

Thanks.

The signature is also explained in Bullnose Forum/Forum FAQ's.  Hope that helps.

On the tank, you should look at the page in Documentation/Fuel Systems/Fuel System Part #'s/Fuel Tanks.  From that you can tell which tanks will swap.  But the '85 tank should fit the '86 if the wheelbase is the same on both trucks.

[Nemesis F150]

The rear tank doesn't cost that much. If the tank from the parts pickup has been sitting with gas and any water in it, most likely it'll have some rust. Also, the fuel pump/sender has a filter on the bottom that might be plugged. Given the hassle of changing tanks it may be worthwhile to just go with a new tank. As for the pump/sender, that could be cleaned and tested.

Don't know what anyone else would have to say about using a tank with a rusty interior. Once it started, will it continue?

[Gary Lewis]

Nemesis F150 wrote

The rear tank doesn't cost that much. If the tank from the parts pickup has been sitting with gas and any water in it, most likely it'll have some rust. Also, the fuel pump/sender has a filter on the bottom that might be plugged. Given the hassle of changing tanks it may be worthwhile to just go with a new tank. As for the pump/sender, that could be cleaned and tested.

Don't know what anyone else would have to say about using a tank with a rusty interior. Once it started, will it continue?

Amen!

Once upon a time I tried to clean an old tank.  I put a few gallons of fresh gas in it as well as a chain and sloshed it around for several minutes.  Poured that out and did it again.  A total of four times, and still was getting gunk out.

But by then I'd invested quite a few dollars in gasoline alone, so I installed the tank.  And sure enough I had fits with the stuff in it plugging up the carb.  I finally had to resort to running two fuel filters back to back and that seemed to solve the problem.

Since then I put in new tanks.

[Perkinator]

Thanks for the info yeah I really don’t want to be dealing with all that trouble. Looked up a tank like you said isn’t to much 80 bucks good thing is can use all this hardware. I’ll probably pull the tank from the F250 to get the hardware and take a look inside not to sure how long it’s been sitting I know my friend used it but not sure when it finally stopped running. I’ll post update when I get the tank off 85

[Perkinator]

Do not want to go through all that if this tank is rusted will invest in new tank. Thank you would have probably tried cleaning and sealing it and ended up spending enough to make buying the new tank worth it.

[Nemesis F150]

Something else to check in to:
The Spectra tank that I ordered did not come with sealed openings so I can only assume it was as it came off the assembly line. Somewhere I came across a "fuel tank cleaner" for use with prepping a new tank but don't remember where I read it.
[Edit: the rear tank install has been put on hold while I take care of a number of outside projects before the rains and cold weather makes doing them too difficult]

Also, ...  LMCtruck.com has a Fuel Tank Sealer, something that may be of interest. Haven't researched this, either. This is from their 2018 digital *.pdf catalog:
Fuel Tank Sealer coats the inside of your tank to stop rust and seal pinholes and weld seams. It’s a non-porous, flexible film that is resistant to all fuels, alcohols and fuel additives. This environmentally safe sealer does not contain the harmful chemical Methyl Ethyl Ketone (MEK) and is non-flammable. Cleaner Degreaser and Metal-Prep must be used to prep fuel tank prior to using fuel tank sealer.
PART DESCRIPTION 37-8488-F FUEL TANK SEALER 1 PINT 37-8489-F FUEL TANK SEALER 1 QUART
PRICE $24.95 $42.95

[grumpin]

I used MEK throughout my career…explains a lot!