As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE WORKING ASA TASK CARD NG-36WC-00001 PG15 STEP L FOUND BUBBLES FROM LOOSEN SENSE LINE ON HIGH STAGE REGULATOR #2 ENGINE. GROUNDED - YES. REMOVED AND REPLACED HIGH STAGE REGULATOR PER B737-900 AMM 36-11-07. HIGH STAGE REGULATOR INSTALLATION TEST REQUIRED. PERFORMED INSTALLATION TEST ON #2 HIGH STAGE REGULATOR BY ALTERNATE METHOD REF APPLICABLE STEPS OF AMM 36-11-07. INSTALL TEST GOOD. LEAK CHECKS GOOD.