904 automatic transmission not shifting on any gears

Ok I’m actually having a similar issue. Fluid won’t flow as far as I can tell. Car was running and driving fine. Parked went inside got in the next day and it refused to go into gear. I’ve checked fluids and can’t get an accurate reading in neutral or any gear at all. It’s like the fluid isn’t pumping at all. Linkages are in great shape and seem to be adjusted correctly so I’m not really sure what’s going on. Fluid condition is good as far as color and smell. No burnt smell or nothing. A904