As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT 12,000 FT, RECEIVED EMERGENCY PARKING BRAKE ACCUMULATOR LOW WARNING LIGHT. COMPLIED WITH QUICK REFERENCE HANDBOOK AND LIGHT EXTINGUISHED, 3 MINUTES LATER LIGHT ILLUMINATED AGAIN. RETURNED TO FIELD AND LANDED WITHOUT INCIDENT. FOUND HYDRAULIC CHECK VALVE DEFECTIVE. REPLACED VALVE IN ACCORDANCE WITH DORNIER MAINTENANCE MANUAL 29-21-09, OPERATIONAL CHECK GOOD.