As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW - FLT 2260 - EN ROUTE DFW-ORD, DURING TAXI OUT, DETECTED SMOKE AND HAZE IN COCKPIT AND CABIN. RETURNED DFW GATE WITHOUT FURTHER INCIDENT. REPLACED WATER SEPARATOR BAGS. TIGHTENED LEFT SIDE HYDRAULIC B-NUT LINE. PERFORMED PACK BURNOUT CHECK PER THE MM. NO SMELL OR SMOKE NOTED. LEAK CHECKS GOOD. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)