Rear Gas Tank Replacement

[demccus]

A while ago I was underneath the bed of my F250 Crew looking at what it'll take to build me a new bumper, when I noticed an ooze coming from one of the tank hold down straps on the rear tank. I dabbed a little on my finger and of course, it smelled like gas...a leak. So I've ordered and received the replacement tank and now I have a question. What's the best way to relieve the pressure from the fuel injection system without using any special tools? I'm thinking that a rag and a toothpick at the Schrader valve should do the trick...any comments/help?

 

[flareside_thunder]

First off nice crew cab in your avatar. Secondly I have yet to use and special tools to relive the pressure build from an EFI system....you should be good to go just make sure you've got the AC/fuel line removal kit.

 

[Fellro]

Unplug the pump relay or fuse, and fire it up for the moment...

 

[70torino429]

just take a small screwdriver and stick it in the schrader valve on the fuel rail to relieve the pressure, itll squirt for a second and be done with it. Then you can get under the truck and disconnect the lines at the tank without worrying about fuel squirting into your face at 30psi. (no, it doesnt taste good btw.)

 

[tomtoc]

just take a small screwdriver and stick it in the schrader valve on the fuel rail to relieve the pressure, itll squirt for a second and be done with it. Then you can get under the truck and disconnect the lines at the tank without worrying about fuel squirting into your face at 30psi. (no, it doesnt taste good btw.)

where is the schrader valve and what does it looks like?

i usually go with the fuel in the face method.

 

[70torino429]

where is the schrader valve and what does it looks like?

i usually go with the fuel in the face method.

Should be on the top of the drivers side fuel rail which is attached to the top of the lower intake manifold and the fuel injectors. There may be a little cap on it that you will need to remove to depressurize it. It looks just like the end of the valve stem on a tire, and works the same way.

 

[splitshot]

Depending on the mileage, might consider replacing the fuel pump while you have it out.

 

[Black150]

I always flip the inertia switch while the engines running and just wait til it stalls out. Then i crank it a few more times to make sure it's fully relieved. The inertia switch should be behind one of the kick panels, usually the passenger side.

 

[70torino429]

I always flip the inertia switch while the engines running and just wait til it stalls out. Then i crank it a few more times to make sure it's fully relieved. The inertia switch should be behind one of the kick panels, usually the passenger side.

starving the engine of fuel is a BAD idea. its much better to just release the pressure with the engine off, then when your ready to start it back up the fuel pump will rebuild the pressure, and you dont have to run the engine out of gas, which is NOT healthy.

 

[Black150]

Other than for safety in a crash, that's what it's there for. It's still doing the same thing, de-pressurizing the fuel system.

 

[Black150]

As far as rebuilding pressure, it's just a matter of resetting the switch and priming the fuel pump with a couple turns of the key before actually firing.

 

[70torino429]

i understand that, but you want to have the engine running and then cut off its fuel supply until it runs lean causing it to stall, lean running conditions are BAD whether it only be for a few seconds or not. the more you do it, the worse. Now, it probably doesnt mean as much on a stock engine, but in certain applications it can cause serious problems instantly. Or you could just depressurize the system like proffesional shops do it with a little screwdriver in the schrader valve which doesnt cause any problems EVER. Your call.

 

[89frankenford]

thats the way i did it on my truck when i rebuilt the motor and replaced the rear gas tank. i put a pen tip on the shrader valve and released the pressure until nothing then i was good to go