bad. Im going to speculate that the easiest way to change it is to remove the bed. Does any one know if that is correct. It actually has dual tanks so when i do it Im changing both.

 

Or drop the tank. Not sure with dual tanks, though, if it's in one of the tanks, or on the outside. I'll see if I can get Chris or Joe to chime in on this one Gary.

 

Yeah Ive heard that removing the bed is actually easier than dropping the tank. lol

 

I didnt think of that hmm. Well maybe its just a tank filter then. All I know is the front tank has been running rough and kind of bogging down. The back tanl runs better but doesnt get as good of mileage

 

It's too bad to drop the tanks-just use pb blaster on the bolts, but the tank drops pretty easily. Another thing to check along with the fuel pumps is the selector valve between the tanks-sometimes one tank will fill up the other tank instead of pumping fuel to the engine. When you say the back tank gets worse gas mileage that is the first thing that came to my mind.

 

Hmm ok Maybe but the front runs out. I run the front tank until its empty then switch to the back. However I have been able to switch back before without adding fuel to the front.

 

So can the selector be set to fill or does it do that automatically when it goes bad

 

Edit "its not too bad to drop the tanks"-I missed the word "not" in my first post. Sorry for the confusion. The selector is supposed to completely separate the two tanks, making them independent systems. When it goes bad, it lets pressure out into the tank that isn't running. If one fuel pump is going bad, then the other tank will run completely normally, the front pump on our truck has been dead for a couple years now, but I changed the rear one a few years back so we aren't too worried about it, just means more frequent trips to the gas station.

 

Ok I will have to look into that. Im not planning on changing it for awhile yet anyways I do alright between the 2 tanks for now

 

What usually happens is the check valve goes bad in those and the reason your front tank fills is b/c the fuel return is just dumping in the front when your running off the back. Jb is right in saying when the fuel pump starts to go they will run back on ya, sometimes they will even do it when the pump is still good, on around the 92ish years there was a TSB that had you put external check valves in the line.

I perfer to take off the box, but we also have a hoist, but it's nothing that 2 ppl can't do, unbolt the box, unplug the tail-lights, take of the filler hoses and lift. Then have a couple saw horses or a few barrels handy nearby. Take off the tailgate first if you want to, less weight.

I'd take a fuel psi reading on both tanks, on the newer ones (such as yours) the check valves are part of the pump, the older ones, such as an 87 had the selector seperate on the frame rail w/ a common pump. I know not everyone has a fuel psi gauge at their disposal, but fuel pumps are pricey, it's always nice to know for sure, but since it's back feeding into your front tank I'd say your on the money with replacing the pump.

 

running a tank out of gas is bad for them,fuel keeps them cool, think we have a couple trucks here that has bad pumps cuz of running them low and never run the mixed gas ,straight regular,we get people in here all the time wanting used pumps after they ran the crap gas,just my two cents,lol

 

Yeah i dont mix gas and . The only reason why I run it so low is because the gas gauge reads empty way before it is I can usually put another 40 miles on after it says empty. Ive noticed that happens on alot of fords.

 

So anyone want to guess which one is bad. LOL will cost 300 bucks to replace both of them. Would rather get away with just doing one.

 

That fuel selector valve is deffinately bad though. I filled both tanks and decided to drive on the rear one first. Ive been driving it since Monday with no problems. Today I smelled fuel so I took a look and noticed the truck was wet by the front tank door. I opened the door and started to loosen the cap and fuel started coming out. I guess the back tank overfilled the front. I may just change the rear one first and the selector valve and see what happens.

 

Ummm, I wanna say since the the front is filling while running on the back that the check valve is bad in the front. Plus you had mentioned your truck doesn't run so good on the front tank.