2003 Ford E-350 Diesel Fuel Tank Delamination Problem

For some reason Ford installed fuel tanks that ‘delaminate’ over time, and wreak havoc on the entire fuel system.  Some quick Google-fu reveals this problem is widespread.  The symptoms are basically loss of power, and stalling.  After seeing what happened inside the tank, I’m surprised the truck even started.

Replacing the fuel tank (Part no. F41B) on a 2003 Ford E-350 diesel.

Some tips up front:

Wear gloves, the tank edges are extremely sharp.

Wear nitrile gloves when cleaning the parts.

Always wear safety glasses

If you’re working like me in your driveway, open up the box the new tank came in and lay it out under the van.  It’ll make moving around underneath the vehicle much easier.


Fuel line wrench

(2) Ratcheting straps

Fuel canisters for holding emptied diesel


8, 10, 12mm sockets

14, 17mm ratcheting wrenches 

Flat head screwdriver

Car ramps, chocking
Procedure for removing the fuel tank:

Back the rear wheels up the ramps, and chock the tires.

Disconnect negative terminal on both main and auxiliary battery.

Open fuel cap.  Drain fuel at filter.

Fill and vent hoses
Disconnect the inlet hose right at the fuel door; (3) screws, and (2) screws on bracket holding the main fill hose and vent to a flange on the underside of the body panel.


Busted tank strap
 Loosen tank straps. Use ratcheting straps hooked to the frame to support the tank, and safely lower it.  You need to to be careful not to lower it too much, as the filler tubes, lines and vents are still connected.   

Ratchet straps hooked to the frame rails help immensly
 If your van is like mine, everything underneath is so rusted, it didn’t matter that I hosed the strap bolts down with PB-Blaster, they still snicked right off, and if I didn’t have ratchet straps in place it would have come crashing down.

Emptying the tank is helpful.  On mine, the pipe clamps on the metal fill tube to rubber hoses that connect to tank, were facing straight up.  I couldn’t release them. So I siphoned the tank right thru the fill door.  It helps to have little or no fuel in the tank. 


All lines and hoses disconnected
 Once you’ve lowered the tank just clear of the frame rail, you should be able to get at the fuel filler and vent hoses from the driver side, and the fuel pump and vent line from the passenger side.  Also, disconnect the fuel level cable.  Take note of the vent and fuel line so you connect them properly on installation- but, don’t worry too much as they’re sized differently so misconnecting is impossible.  Once that’s disconnected you’re ready to drop the tank.


Strainer, pickup and float assembly
 On the top of the fuel tank, remove the two vent valves, and put aside.  They have directional arrows to show how to ‘remove’ and ‘install’ (simple 90° turn). You’ll also need to unscrew a keep a small plug near the main opening. Unbolt the strainer/float assembly.  Be careful removing, as the float is very delicate.

Screens were completely gummed up with this silver paint
Half the screen was completely solid with muck
Looks like the pump was pulling fuel thru the relief flap
Strainer showing debris

Splash pan in tank full of flake debris
 Here’s where you’re going to see the carnage.  I first noticed the tank was totally polluted when I started siphoning, but I had no idea how bad it was till I pulled the strainer cover.  Tank was full of silver flakes, and the strainer screen and filters were totally gummed up with silver flakes and goo.  I can’t believe the engine ran at all.  High pressure canned brake cleaner worked great to clean the whole assembly and filters once dissassembled. 

From here, just reverse the removal for installation.  With this problem, you’re gonna want to replace your fuel pump and filter as well.  The good news is, the pump is frame mounted right under the driver seat and it’s a piece of cake.  The bad news is the fuel filter is buried and requires a lot of disassembly and tiny hands to get at.

New tank all ready to go

See You Down the Road!

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