Fuel not transferring between tanks on ProStar

[Pro Star Cummins]

The transfer pump is on top of transmission and hard to get to. to gain access
You need to remove shifter boot . Ours worked,but being it was so hard to get to we decided
To change at home instead of alongside of road. We had continuity tested both
Sending units and read ok. Reason we drained fuel from tanks was to make
It easier to rotate and we replaced fuel lines and fittings too. The tank straps
Were replaced too. One had broken and let tank drop against faring. We are going
To get rid of this truck and rebuild our old Pete. What a nightmare this truck
Is. Never ending problems .we replaced right side sending unit first and had same
Problem fuel would not transfer over. We did jumper pump trick . Final fix was left side
Sending unit . Hope this works for you. We're not professional mechanics ,just trying to
Muddle our way through.lol