As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED, CLIMBING THROUGH 18,000 FT 'A' SYS QTY DECREASED TO ZERO. ALL PROCEDURES ACCOMPLISHED PER CHECKLIST. BOTH 'A' SYSTEM LOW PRESS LIGHTS WERE BLINKING AS PRESS WAS DROPPING. MAINTENANCE FOUND NR 4 L/E FLAP ACTUATOR LEAKING AT SWIVEL END. REPLACING ACT AND ALL COMPONENTS, FILTERS IN 'A' SYSTEM AS REQUIRED.