As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED SUCTION INDICATOR WAS BELOW LIMITS, AC RETURNE TO BASE. UPON TROUBLESHOOTING, THE MECHANIC REMOVED THE AIR PUMP AND NOTICED THE SHAFT WAS VERY EASY TO ROTATE, HAD NO RESISTANCE TO IT. NO PROBABLE CAUSE OR RECOMMENDATIONS AT THIS TIME. (K)