What was found
YELLOW HYD SYS LO PR ECAM CLIMBING THROUGH FL260. COMPLIED WITH ECAM AND QRH. YELLOW SYSTEM RESERVOIR QUANTITY INDICATOR FLUCTUATION IN YELLOW ABOVE AND BELOW RED DOT. ECAM QUANTITY INDICATES STEADY. COORDINATED WITH GOC AND MOC VIA ATLANTA RADIO AND ACARS. GOC/MOC RELAYED OK TO CONTINUE W/YELLOW HYD SYS OFF . - EMERGENCY DECLARED FOR LANDING - INSTALLED HOSE P/N A2714201300000, TAG NR 01612331, PER A300 AMM20-23-11-00-0. INSTALLED LACING TAPE FOR CHAFING PER A300 AMM 20-23-14-00-0. SERVICED YELLOW HYD SYSTEM PER AMM012-12-29-00-0.. CHECKED YELLOW HYD SYSTEM FILTER CLOGGING INDICATORS PER A300 AMM 29-00-00-03-0. YELLOW HYD SYSTEM IS SERVICEABLE AT THIS TIME.