Do fuel tanks cross feed and equalize?

That is pretty much what we have said about our new trucks, even though it's only a single 120 gallon tank, when it reads half a tank, you could put in either 50 or almost 90 gallons! There was no rhyme or reason to why it did that, so it was always just a crap shoot, although didn't really have to worry too much as we never drive enough during day to use a full tank of fuel and usually went home with a full tank.

 

Yes that's because it will take time for the forces of gravity to equalize. The higher tank will exert enough pressure to force the diesel fuel back into the lower tank thus it will eventually equalize.

 

My passengers side tank isn’t drawing fuel. Vents clear. Lines between tanks and shutoff are only a few yrs old. Must be the valve itself. Problem just popped up out of the blue. Tank is full to the top, as if it’s still getting return fuel, just not drawing any. Won’t equalize.

 

Peterbilt? They're notorious for this. Never had one that I didn't have to fiddle with shutoff valves to get equal draw down.

 

2001 Freightliner. The valves never been changed. I’ve always heard they’re a problem. Some suggest replacing it with just a Tee. I like being able to shutoff either if needed. I think a new valves about $200. I’ll try what you said tomorrow.

 

I think that’s the problem. I dropped a small plastic bottle in it a while back. It’s probably melted
around the pickup. I’m hoping I can take the pick up tube out, and remove it. Right now the tanks very full. Still returning fuel.