What was found
WHILE PREPPING A/C FOR TOW FOUND 8 FT LONG BY 4 FT WIDE FUEL STAIN UNDER NR 2 ENGINE AND FUEL DRIPPING FROM BOTTOM OF COWL. GROUNDED-YES. FOUND NR 2 ENGINE TBV (TRANS BLEED VALVE) DRAIN DRIPPING APPROXIMATELY 67 DROPS, PER MIN. RAN NR 2 ENGINE AFTER ENGINE RUN TBV DRAIN HAD APPROXIMATELY 20 DRIPS OF FUEL A MINUTE, REF B737-800 AMM 71-71-00-801-F00. FUEL DRIPS WITHIN LIMITS. REMOVED AND REPLACED THE NR 2 ENGINE TBV, REF AMM 75-23-01/401. LEAK AND OPERATIONS CHECK GOOD, REF AMM 75-23-01-400-801-F00 STEP 3G.