As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
C HYD PRIM 1 EICAS MESSAGE DURING TAXI. AIRCRAFT BACK TO BLOCK AND GROUNDED BY MAINTENANCE. MAINTENANCE PERFORMED A VISUAL AND FUNCTIONAL CHECK OF THE C1 PUMP SHOWED ALL NORMAL. LOAD TEST AND INDICATIONS NORMAL. NO ISSUES NOTED WITH OPERATION. ALL WORK REF B767 AMM 29-11-00. AIRCRAFT RETURNED TO SERVICE.