You got air between the abs pump and the brake system. Under normal condition, the ABS pump is not a factor in braking, it is only when one of the wheel sensors signal the ABS computer that it is not in synch with the other wheel sensors, that is when the ABS computer instruct the ABS pump to start pulsing the wheel that is not in synch with the other wheel (Normally a wheel is out of synch when it locks up). That is why to use the ABS system you need to stand on the brake so that the system can work.
You will need to get a scanner that that can auto bleed the ABS module.
Here a video on using an auto bleed scanner. Note that when he auto bleed the module he has his foot to the floor on the brake pedal. Are you guy doing this with INPA?
https://www.youtube.com/watch?v=fUqmBqYIEAE