As long as nothing comes out of it, no. But it should have high pressure fuel in it, so it sounds like there might be a blockage downstream.

 

When I plugged mine, the other day, by using a stud as suggested in this thread, I put the stud in the line felt like it had a one-way pressure valve in it, specifically inside the metal connector, the return line didn't have one, but the pressure line did. I ran it without the plug and nothing came out.

Near as I can tell that is normal.

 

That is impossible!
The other line is a pressure line from either tank.

 

I deleted the selector valve as well. That is where the filter/steel return went.
Now the fuel tank selector switch is anti-theft device haha.

 

The day conanski and subford are wrong is the day I quit going on ford-trucks. Thanks for the quality posts.

 

a little old 302 eats enough as it is, a bronco tank would be in order for me as I hate having to fill to separate tanks, hence why only one ever gets filled half the time and sometimes gets switched around to keep the other tanks pump alive. I don't know why but I just hate the feeling of being done filling one and having to stop and move on to the other one.

 

I couldn't bring myself to buy the less expensive replacement pump and hanger, so I went with Motocraft. But that did seal my decision to remove the rear tank. Now, to plugging the fuel lines, I like Conanski's solution, but that looks like it would plug at the end of the supply/return fuel lines, and I don't want to leave that much fuel line.



This means I'll be cutting the braided fuel lines and plugging with a bolt or rod to fit the inner diameter and clamping with hose clamps. I found this OTC Tools plug but I don't see a good description of its use. Does this look like it would lock into the connector like Conanski's fab'd bolt?





But eventually it seems like the best solution is to replace the double function reservoir with a single function reservoir and be done with the patch work.

I've not had a lot of luck finding this work around, but I may be using the wrong phrases. I don't want to hijack this thread so let me know if I'm getting off topic.

 

Your 1996 truck does not use a double function reservoir or a single function reservoir.
All the fuel lines from the tanks on your truck just go to a "T" fitting at the frame and then the pressure line goes to the filter and the return line goes to the fuel pressure regulator.

 

Thanks Subford. I didn't drop the tank to do this so I was sure it was hidden between the tank and frame.

After reading about this issue of leaving or removing the second tank, I feel a lot more comfortable leaving the defective pump in the second tank and disconnecting the power. It's still not clear to me what keeps fuel from entering the rear tank if there's no power to the fuel delivery module or check valve though. Is it the check valve on the working tank that prevents fuel from flowing to the rear? Or is it the design of the pump to not allow fuel to flow in from the high pressure side whether there is power or not?

I can't find the thread now where I read the suggestion to do this, but this solution gives me the option of at least adding a cheaper pump later to get both tanks back online again.

 

Neither. It's the check valve in the rear FDM that keeps fuel from flowing to the rear when using the front tank.

 

So if I leave the power disconnected from the rear tank, should a spring keep the check valve closed and prevent fuel from back flowing into the rear tank? And I suspect this works so long as the check valve actually seals, otherwise I guess fuel will transfer to the rear tank.

Even then there's the shuttle valve that could let fuel flow in, so all this puts me back to needing to plug the rear fuel lines by fabbing a plug like subford showed, or plug the fuel lines inside the hanger assembly. Plugging the hanger fuel lines seems best since that keeps everything in place if I ever decide to spend money on another Motorcraft pump, or buy a cheaper pump and call it a backup.

This thread has helped me understand the dual tank system on my truck so much better than the Haynes or online searches.

 

Electrical power does not operate the check and the shuttle valve. They are spring loaded and fuel pressure operated.
If the pump runs in the FDM then the fuel pressure will open the shuttle valve to let fuel back in and also force open the check valve in the FDM.

 

Thanks Bill. I'm really happy with this solution since everything is in place for later when I'm willing to spend the money to get the rear tank back in service. Much better than removing the second tank. This thread was extremely helpful.

 

I cut the tank side chunk of lines off, pinched them and welded them and reinstalled them on the truck. My front tank was a leaker when I bought it. When I decide to put the front tank back it its a simple swap.

 

I'm planning on deleting my front tank in my "hot rod" f150, due to the fact that the tank is leaking, the pump is growing weary, and because it no longer serves as a daily driver, i see no point in having the dual tanks. when the big block comes, then i will run symmetrical duals, but one of the things i like best is the wight balance. i occasionally run autocross, so having the weights similar side to side actually does make a difference.

My plans to block the lines were that i took a dead fuel pump assembly fr4om a truck in this series, i cut the two fuel lines off the top plate ofthe pump, and then i soldered them shut/crimped the ends. does anyone else see a problem in that method?