What was found
ETOPS - DURING TAXI IN, APU BLEED SELECTED ON TO CONFIRM PACKS 10 MINS AFTER SELECTING ON, OBSERVED AN INTENSE BURING ASPHALT/CHEMICAL ODOR IDENTICAL TO PREVIOUS TEST FLIGHTS. REMOVED #2 RT OZONE FILTER IAW AMM 21-51-41 TO FOM FOUND CONTAMINATED. INSTALLED #2 OZONE FILTER IAW AMM 21-51-41. OPS & LEAK CHKD OK. REMOVED #1 LT OZONE FILTER IAW AMM 21-51-41 TO FOM FOUND CONTAMINATED. INSTALLED #1 LT OZONE FILTER IAW AMM 21-51-41. OPS/LEAK CHKD GOOD. REPLACED RECIRC FILTERS IAW AMM 21-21-41. SECURITY CHKD GOOD. OK FOR SCV. INSP IP CHK VALVE IAW AMM 36-11-41-200-801-A. NO CONTAMINATION, DUCTING GOOD. REINSTALLED DUCTING & IP CHK VALVE. LEAK CHK FAILED. FOUND LEAK AT PRV FWD CLAMP. TIGHTENED #1 ENG PRV CLAMP. RAN ENGINE BLEED 10 MIN. LEAK CHKD OK. ALL OPS & LEAK CHKD GOOD. NO DEFECTS.