What was found
ON TAKE OFF ROLL @ 60 KNOTS RECIEVED ECAM ALERT FOR YELLOW SYSTEM LOW PRESSURE. REJECT THE TAKE OFF AND RETURN TO GATE (NOTE: CREW REPORTED SYSTEM PRESSURE RETURN TO NORMAL DURING TAXI IN) REMOVED AND REPLACED YELLOW SYSTEM HYD QTY TRANSMITTER. REF AMM 29- 31-11-04. OPS AND LEAK CHECKS GOOD. PERFORMED ENG RUN IAW JRH CHAPT 6, WITH 40K OF FUEL ON BOARD AND EIGHT LOADED TO SIMULATE PAST CONDITIONS. ENGINE RUN DURATION WAS 25MINUTES, AND ACCOMPLISHED AT VARIED POWER SETTINGS. CYCLED ALL FLIGHT CONTROLS, FLAPS/SLATS AND STAB AND DID NOT RECIEVE A YELLOW ENG PUMP LOW PRESSURE ECAM OR OVERHEAD ALERT. INDICATED PRESSURE FOR YELLOW SYSTEM WAS STABLE BETWEEN 2900- 3050PSI. YELLOW SYST FIRE SOV INDICATION ON MAINTENCE PANEL WAS SHOWN AS OPEN AND DID NOT FLICKER OFF DURING RUN. YELLOW QTY INDICATION WAS STABLE WITHIN THE TOP HAT OF THE INDICATAOR DURING RUNS AND DID NOT VARY AS NOTED ON PREVIOUS DISCREPANCIES. AIR PRESSURE ON RESERVOIR WAS 50 PSI PRIOR TO AND AFTER ENG RUNS. NO FAULTS NOTED AT THIS TIME FOR YELLOW ENG DRIVEN PUMP. PERFORMED FUNCTIONAL TEST OF YELLOW SYSTEM FIRE VALVES AND ASSOCIATED INDICATION SYSTEM ANDOPS TEST OF YELLOW HYD SYSTEM REF A300 AMM 29-10-00-05. NO FAULTS NOTED.