As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDIS 682 29-10 9603 08JUN21 JFK OPEN U AT FL 240 RECEIVED ECAM WARNING FOR YELLOW HYD SYSTEM LO PRESSURE. AFTER ANALYZING WE FOUND LOSS OF ALL YELLOW HYDRAULIC FLUID. RAN QRH, DECLARED EMERGENCY AND LANDED. AMM: 27-14-21-04 REMOVED AND REPLACED YELLOW ISOLATION VALVE LOCK AS PER M.M. 27-14-21-04. OPS CHECK ANDLEAK OK. RAN BOTH ENGS AND EXCERSISED FLT CONTROLS TO BLEED SYS. SERVICED HYD SYS TO HOP HAT M.M. 12-12-29-00 AND RE- EXCERSIDED FLT CONTROLS.