As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING AICRAFT PUSHBACK A HYDRAULIC LEAK WAS NOTICED OVER RIGHT MAIN GEAR. AIRCRAFT BACK TO BLOCK AND GROUNDED BY MAINTENANCE. MAINTENANCE FOUND "O" RING LEAKING ON ANTISKID VALVE. MAINTENANCE REMOVED AND REPLACED O-RING ON ANTISKID VALVE IAW AMM 20-10-19 LEAK CHECK GOOD. LEAK CODE 600-9-B. AIRCRAFT RETURNED TO SERVICE.