My right tank is pulling fuel so I only fuel left tank. I don't see a hose that connects the two of them. Fuel from my left tank somehow gets into my right tank and takes away from my usable fuel. Any help would be greatly appreciated. C15 mbn
Your truck draws from the left tank and the fuel returns to the right tank. Does your truck shut down out of fuel with the left tank empty and the right tank full?
Look at your tank vents and fuel return lines. Either could be plugged or collapsed to the point of preventing flow.
Pete's draw and return from both tanks. There is like a Reed valve on the return that basically senses pressure and returns fuel to the appropriate tank. That can get crap in it and stick one way or another. Or most likely your tank vent is plugged and pressuring a tank so fuel doesn't return to it.
Then so magic voodoo happens when you park and the tanks will even out, or if parked on a slope it will go to the low side. Surface tension or siphon or something.
Pull your tank vents and see if you can blow air through them