Hi! Thanks for using Justanswer.com! I'll try to help with your concern. Bleeding the brakes can sometimes be very difficult even if you do things the right way. There are many ways of bleeding brakes (gravity, vacuum, pressure) because of this. You didn't need to do anything to the valve before installing it, you would just bleed the brakes as normal after installing it of course.
My suggestion is to try to crack the lines coming off the master cylinder as an assistant provides solid brake pedal pressure and see if you get any air there. If you do, repeat until you don't have any more air and then retry to bleed the brakes again with the conventional method. Also, if there is any pedal at all, I drive cars around the lot for a while if possible. That seems to help get the air out when the lines are reopened. Try these suggestions and let me know if it helps.. If not we can try some other things. Thanks again!