Leak in fuel tank any suggestions on where to get second hand tank

Rusted or broke fuel lines.

Well, you need a quick tutorial on your fuel system. Now to find a leak, stop trying to start the engine. You are only adding electrical charge to an already dangerous situation. Now stop and think this through. Modern fuel injection requires fuel under high pressure to operate. The injectors are immersed in this pressurized gas, as are the lines leading to them from the fuel tank's fuel supply line. So just by turning the key to ON, not start, you have initiated the process to start the engine, and that means the pump has operated for 2 seconds to put the fuel system under high pressure.

Now if you follow the fuel supply line (from the gas tank) to the engine connection, start here to find a leak. It is now under high pressure from here to the injectors on the engine- one for each cylinder-it should be dripping with gas somewhere. You could even turn the key to off after the pump has ran for 2 seconds. The fuel system is designed to hold pressure in the system for about 10 to 15 minutes, before slowly bleeding off. Enough time to search for a gas leak. A couple of other things associated with the system: there will be also a fuel return line from the injector rail, it goes back into the gas tank. both the supply line and the return line often run alongside each other. There is also a fuel pressure regulator, immersed in the fuel rail, a seal on that may have started leaking. If an air breather housing, or some cover prevents your seeing the fuel system entirely, then set it aside. You should be able to find the leak. Just be careful, have lots of rags handy, happy hands are learning hands.

check and see if there is still a leak when you are not putting gas in it if it is still leaking, lower the tank and check all the hose connection for leaks. replace hose and clamps turn key to run but not start with tank lowered look for leaks

Disconnect the cable to the battery's negative terminal with a socket wrench. Loosen the filler cap on the fuel tank to relieve the pressure in the fuel tank. Drain the fuel tank by siphoning the fuel into a gasoline container with a hose. Raise the rear of the vehicle with a jack and support it on jack stands. Release the clamps on the hoses for the filler neck and vent tube of the fuel tank. Support the fuel tank with jack stands and detach the support straps for the fuel tank. Lower the fuel tank slightly and disconnect the electrical connections and hose on the fuel tank. Remove the fuel tank from the vehicle.

Turn the retaining ring on the fuel sender assembly counterclockwise with tool . Remove the retaining ring. Lift the fuel sender assembly out of the fuel tank and pull the fuel pump into the attaching hose while holding the bottom support of the fuel pump in place. Discard the O-ring on the fuel tank.

Install the new fuel pump into the attaching hose of the fuel sender assembly. Use care to avoid bending the fuel strainer since this will restrict fuel flow. Place a new O-ring on the fuel tank and install the fuel sender assembly into the fuel tank.

Place the locking ring on the fuel sender assembly and turn it clockwise with tool until the ring locks into place.

Install the fuel tank by reversing step 1. Pressurize the fuel system by turning the ignition on for two seconds and turning it off for 10 seconds. Turn the ignition on and check the fuel lines for leaks.

Hello
Having worked for Ford for 25 years and having seen this very same problem (fuel flows between tank and overflows) many times there is only one cause of the fuel flooding the other tank, the fuel switching valve on the frame rail under the truck is detective, this valve contains special silicone rubber poppet valves that open when the front or wear tank fuel pump is selected, it then seals when the tanks electric pump is shut off at the selector switch, your poppet valves are leaking, all to a common problem. Back in 2000 when I retired this switching valve was no longer sold by Ford parts, it is obsolete. I suggest you check with Ford to see if it is available from some other source or call a local parts store like NAPA or Carquest and inquire is anyone in the aftermarket has them. The last choice is a used one, but of course it could have the same problem as yours as age and deterioration of the rubber valves is what makes them leak.

There are fuel lines inside the gas tank. Over time they can rust causing them to break or leak. You have one of two options, first you can pull the tank and replace the line. The second option is to keep the gas tank fuel level above the leak. And the fact that this happens mainly when going up a hill, suggests the leak is lower in the tank. All the gas shifts to the rear of the tank and exposes the leak. NOTE: The leak is probably just above the level you usually keep the tank filled to. So if you keep it at 1/4 that's where you'll find it etc....

i had the same problem and had a custom tank
made coast a little but will never rust .
made out of alloy

These units are in the tank and must be dropped in order to replace.


WARNING Do not handle the fuel sender assembly by the fuel pipes. The amount of leverage generated by handling the fuel pipes could damage the joints.

1. Relieve the fuel system fuel pressure, as outlined in the Fuel System Section.
2. Drain the fuel tank to at most 3/4 of a tank full.
3. Raise the vehicle.
4. Remove the fuel tank.
   NOTE The modular fuel sender support assembly will spring-up when the locking ring is moved.
   
5. Remove the fuel sender assembly using tool J39765 Fuel Sender Locknut Wrench or an equivalent.
6. Note the position of the fuel sender strainer for installation.
7. Support the reservoir with one hand and grasp the fuel sender strainer with the other hand.
8. Pull the external fuel sender strainer off of the fuel sender.
9. Inspect the fuel sender strainer. If the fuel sender strainer is contaminated, the fuel tank should be cleaned.
10. Discard the fuel sender strainer after inspection.
11. Disassemble the electrical connectors from the fuel level sensor assembly of the fuel pump and cover assembly.
12. Disassemble the fuel level sensor assembly.
    
    

    Fig. Fuel level sending unit on fuel sender (fuel pump) module.
    

To install:

1. Assemble the fuel level sensor assembly.
2. Assemble the electrical connectors to the fuel pump and cover assembly.
3. Position the new fuel sender strainer on the modular fuel sender and push on the outer edge of the fuel sender strainer until the fuel sender strainer is fully seated on to the sender assembly.
4. Install the fuel sender assembly into the fuel tank using tool J39765 Fuel Sender Locknut Wrench or an equivalent.
5. Reinstall the fuel tank.
6. Lower the vehicle.
7. Add fuel to the fuel tank.
8. Connect the negative battery cable.
9. Reinstall the fuel tank filler pipe cap.
10. Inspect for fuel leaks.
11. Turn the ignition switch ON for 2 seconds.
12. Turn the ignition switch OFF for 5 seconds.
13. Turn the ignition switch ON .
14. Check for fuel leaks.

First...this is where the pump is (gas tank) on the engines listed:



Illustrating fuel pump and sending unit sensor (3) on 1999-2005 4.8L, 5.3L, 6.0L Engines


Removal & Installation

1. Before servicing the vehicle, refer to the Precautions section.
   
2. Remove or disconnect the following:
   
   • Negative battery cable
     
3. Relieve the fuel system pressure.
   
4. Drain the fuel tank.
   
5. Remove or disconnect the following:
   
   • Fuel tank
     

WARNING Do not handle the fuel sender assembly by the fuel pipes. The amount of leverage generated by handling the fuel pipes could damage the joints.

• Fuel sender assembly retaining ring using a fuel tank sending unit wrench. Remove the fuel sender assembly and the seal. Discard the seal.
  

Note the position of the fuel strainer on the fuel sender. Support the fuel sender assembly with one hand and grasp the strainer with the other hand. Pull the strainer off the fuel sender. Discard the strainer after inspection. Inspect the strainer. Replace a contaminated strainer and clean the fuel tank.

• Fuel pump electrical connector
  
• Electrical connector retaining clip from the fuel level sensor
  
• Sensor electrical connector from under the fuel sender cover
  
• Fuel level sensor retaining clip
  

Squeeze the locking tangs and remove the fuel level sensor.

Remove the fuel pressure sensor.

To install:

1. Install or connect the following:
   
   • Fuel pressure sensor
     
   • Fuel level sensor
     
   • Sensor retaining clip
     
   • Electrical connector to the fuel level sensor
     
   • Electrical connector retaining clip to the fuel level sensor
     
   • Fuel pump electrical connector
     
   NOTE Always install a new fuel strainer when replacing the fuel tank fuel pump module.
   
   
   • New fuel strainer in the same position as noted during disassembly. Push the strainer on the bottom of the fuel sender until the strainer is fully seated.
     
   • New seal on the fuel tank
     
   NOTE The fuel pump strainer must be in a horizontal position when the fuel sender is installed in the tank. When installing the fuel sender assembly, assure that the fuel pump strainer does not block full travel of the float arm.
   
   
   • Fuel sender assembly into the fuel tank
     
   • Fuel sender assembly retaining ring
     
   • Fuel tank. Install the fuel tank strap attaching bolts. Tighten the bolts to 30 ft. lbs. (40 Nm).
     
2. Refill the fuel tank. Install the fuel filler cap. Connect the negative battery cable.
   
3. Turn the ignition ON for 2 seconds.
   
4. Turn the ignition OFF for 10 seconds.
   
5. Turn the ignition ON.
   
6. Inspect for fuel leaks
   

no
it is more likely that the problem is in the EVAP system
code p 0455 refers to evaporative emission(EVAP)system---large leak detected ====causes --hose connections ---intake leak---EVAP cannister---EVAP canister purge valve
I would suggest to you to tell the mechanic to replace the EVAP purge valve as the problem is more likely to be that than the fuel tank