As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LOST NR 1 HYDRAULIC SYSTEM PRESSURE WITH NR 2 ENGINE RUNNING DURING SINGLE ENGINE TAXI. NO NORMAL BRAKING. I/B ROLL SPLR, RUD HYD AND RUD FULL PRESS CAUTION LIGHTS ILLUMINATED. NORMAL BRAKING RETURNED DURING RETURN TAXI TO GATE. MAINTENANCE COULD NOT DUPLICATE DISCREPANCY. CYCLED NR 1 STANDBY PUMP CIRCUIT BREAKER AND CLEANED ASSOCIATED CONNECTORS AS A PRECAUTION.