360 break-in

As many of you know, I have rebuilt a 1975 360 for my '67 Dart. Well, it has fired off and everything went well. Ran her for about 25 minutes at nothing below 2300 rpm (verying up and down during that time). I bought a few parts from the forum members here, and everything worked out great. These forums are outstanding. The only issue I had, was I replaced the Saginaw steering pump and is connected to the factory steering gear. I had great power steering through out break in and fluid was full. No noise at near full rotation in both directions. Then all of a sudden no power. Pump was still turning and pulley shaft is not loose. I have been told it might be the rear connection on the pump, (screen on high side). I have an adjustment screw on the gear, could that be the issue? Any input would be great. Thanks. Also, I know how to post pictures, are videos done in the same manner.? I know you all love your ****.