As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURIING CRUISE, WHEN WE SELECTED GEAR UP WE GOT A C HYD QTY WHEN SELECTED GEAR DOWN WE LOST THE REST OF OUR C HYD FLUID (C HYD PRESSURE LIGHT ILLUMINATED). EMERGENCY DECLARED. ABORTED APPROACH. FOUND LEFT LEADING EDGE SLAT DRIVE CONTROL VALVE LEAKING. REPLACED LEFT LEADING EDGE CONTROL VALVE MODULE IAW B767 AMM 27-81-12 SYSTEM OPS NORMAL NO LEAKS NOTED. AIRCRAFT RETURNED TO SERVICE.