Fuel problem international 8600

Does it draw and return to same tank or , draw from one - return to the other?

 

There is a crossover between the tanks. Many times there are valves at both tanks. One may be closed.

Or your tank isn't venting and as the fuel drains, it creates a vacuum which prevents the fuel from equalizing.

 

It depends on how it is setup, but a lot of those trucks do not have a cross over to balance the tanks rather they draw from both to a central location then to the engine and a return to another central location then to each tank. It may be that the draw line from the one tank has a shut off valve or plugged.

 

You need to see if your truck uses a small electric transfer pump to transfer fuel from that tank to the main tank. Usually the passenger side is the "storage" tank and the drivers side is the "draw" tank that engine draws from and returns to. The pump is usually located on the frame rail near the storage tank, or at the back of the engine over the transmission bellhousing. If you have the electric pump, this is computer controlled by the body controller as it monitors fuel levels in both tanks. If you do have the electric pump, then it can be diagnosed with Diamond logic builder software.

 

That truck most likely has a transfer pump the fuse is in the glove box area is known for lost contact . Check voltage and ground at pump with truck running if it has both the pump is bad if it's missing than its either sending unit or wiring