c4 transmission testing

I've recently rebuilt my c4. I air tested the clutches and all. worked fine. when I put everything back together, reverse, but no drive. took the valve body out, air tested again, its ok. tore the valve body apart and checked that the valves were free. put it back together. same issue. any ideas? is there a way to test the valve body?

Thanks, and I apologize if this has been discussed before. still learning how to search the forums