Rebuilt 727 slow to no engage

If you have a constant 2 - 3 flare, one of the two steel sealing rings for the reverse/high clutch on the reaction shaft may have been damaged unnoticed while refitting the pump. This is very easily done on an early 727 due to the narrow reverse/high clutch drum bushing which doesn't provide much of a guide while dropping the pump in. A broken sealing ring here would manifest itself by a loud hiss during the air pressure test if one was carried out before installing the valve body.