Tractor Repair: Diesel tank cleaning/removal, fuel line filter, nuts and bolts

Question
I have a 2005 Kubota B3030 diesel with 630 hours.  I loose power at high RPM.  When I move to 2400 RPM for a minute or two, my fuel line sediment cup/filter begins to fill up with air at the top of the cup.  Approximately a minute later only 1/2 of the sediment cup is filled with fuel, the engine is starved and it begins to chug.   If I shut the engine off, the cup re-fills quickly. It seems that fuel is pouring into the cup freely.  At idle it takes a couple minutes to re-fill. I have removed the fuel line aft of the lift pump to see if it is working well.  There is a solid pumping of fuel through it so I don't think it is weak.  I have bleed the system at the sediment cup, lift pump, and at the injectors to identify if their is air in the system.  I'm not sure but this does not seem to be the problem unless there is a small air leak somewhere that is sucking air into the system at high RPM. I don't seem to have any leaks in the fuel line. I have replaced the fuel line filter.  The fuel line tubes seem to be fresh and flexible.
Question: Do you think that there is a fuel tank/fuel line blockage and recommend that I remove and clean the diesel tank?
~Also~ I don't know how to remove the tank and would appreciate any help you can offer on how to take it out for cleaning.
Thank you

Answer
Sorry for the slow response season is here and I am busy, busy. I would suggest draining the fuel using compressed air to blow back through the lines and letting all the fuel dry and use a vacuum to suck out the debris. Taking the tank off could be a major job that you might not want to tackle. But it is just nuts and bolts so it cant be to hard.