so i have been out of town and in the mean time my parents have been driving my truck. my mother is complaining that it has been drinking fuel. when i get back i am not going to have to drive it across country. so i wondering what is the easiest way to find fuel leaks. also i have heard of people having one tank draining into the other. cross filling i think it was called. well my rear tank has a bad pump and leaks. so that tank filling up would be bad.

so what is the part that fails that causes the cross filling and how easy is it to check?

oh ya my truck is a 94 f150 5.0L automatic

 

You could just replace your back tank haha

 

The pumps have a built in check valve system. The check valves/ pumps in BOTH tanks work together to route the fuel properly. If the check valves in one or the other, or both are not working, then excess fuel returning from the engine EFI system could be sent to the wrong tank. What actually happens depends on which valve(s) are stuck open or closed.

It's a real pain to have to drive long distances with only one tank and have to fill up every 150 miles. BTDT.

 

ya i wish i could just replace the rear tank but i cant afford it right now. i got a big move coming up. where could i block the line to prevent it from filling the rear tank. i may just remove and junk the rear tank for now and block the line. the rear pump doesnt work anyways.

 

The way to fix it is to fix the back tank. Or replace all the fuel lines for a one tank system. Or park it. Take your pick.

 

ok say my finances are good enough to swing the repair. it looks like i can get the tank on ebay for under 100 shipped. but how do i know if i need the 18 or 19 gal. also it looks like i can get the pump for around 60. i have yet to find the pre-bent fuel line though. anything else i should be looking for?

but i also need to know the best way to check for other fuel leaks as well.

 

There is no prebent fuel line. All the lines are flexible, plastic or braided stainless steel.

 

When I redid my rear tank I just used rubber fuel line and hose clamps and abandoned the nylon lines. You can buy the Ford quick connect splice in or repair fittings if your prefer.

Checking for leaks - Your eyes and nose.... It's either dumping fuel onto the ground or it's not.

For the tank make sure you are getting the one for the rear (after axle).
Go to online autoparts store like Autozone and specify your year and model etc.... and see what you come up with.

The pump is only part of the system. You may need a sender as well.

 

thanks guys for the info

 

so my dad just got back to me. so the rear tank is leaking fuel when there should be none in it. so ya that is going to be fixed as soon as i get back to it.