I have the hotfix installed. If I depress brakes and drain all the pressure out of the accumulators, I press the system B AC pump to pressurize it, but it only goes to about 900 psi, and I still get a "low brake press" annunciator which means I can't set the parking brake. Is this correct? I've seen the video you posted, but that is with the engines running (ATMs pressurizing system B). Shouldn't the system B pump generate enough pressure to depressurize the accumulator after depletion?