As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HYD PRESS ON LIGHT CAME ON INFLIGHT. COMPLIED WITH PILOTS ABBRVT CHECKLIST (J2). LIGHT REMAINED ON UNTIL ON FINAL AND GEAR WAS EXTENDED. TROUBLESHOT SYSTEM AND REMOVED HYDRAULIC BYPASS VALVE, INSTALLED A NEW BYPASS VALVE. REMOVED HYD SUB PANEL PRESSURE SWITCH AND INSTALLED A NEW PRESSURE SWITCH, OPERATIONAL CHECKS GOOD AT THIS TIME IAW CE560 M/M 29-11-06.