As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING GROUND RUN UP OUTPUT OF ENGINE DRIVEN DRY AIR PUMP FAILED TO PUT OUT PROPER PRESSURE AT IDLE RPM. RAN AIRCRAFT UP AND AIR PRESSURE STILL LOW AT HIGHER RPM. PROBABLE CAUSE IS HEAT AND VANES WEARING ON THIS DRY AIR PUMP. RECOMMENDATION FOR CORRECTIVE ACTION IS MAKE THIS A LIFE LIMIT PART AND CHANGE AT 500 HOURS.