What was found
ACRID FUMES & HAZE FROM A/C VENTS ON TAKEOFF. SECURED PACKS & BLEEDS & HAZE APPEARED TO CLEAR. LANDED NORMAL & SHUT DOWN ENGINES. TOWED TO GATE. INSTALLED APU PRESSURIZATION CHECK VALVE. PURGED & CLEANED ALL LINES & DUCTING AS NEEDED TO REMOVE RESIDUAL HYD FLUID CONTAMINATION. VERIFIED PROPER HYD SERVICING. CLEANED AIR PIPES & CHECKED FOR CONTAMINATION. DISCONNECTED SEVERAL DUCTS ON PACK 1 SYS TO CLEAN. INSPECTED RESERVOIR PRESS. FILTER GOING TO PACK. PURGED & CLEANED LINE. REPLACED APU PRESSURE CHECK VLV. PREFORED HYD RESERV SYS LEAK TEST. LEAK TEST GOOD. RAN BOTH ENGS & PREFORMED CLEANING & OPS OF BOTH PACKS. NO SMOKE, VAPOR, OR CONTAMINATION. ACFT OKAY FOR SERVICE.