The ESES 2002 wind pump, a 4.6 m rotor diameter high-performance water pumping windmill, was tested at four different sites (Cairo, Giza, Wadi El Natroun and El-Tot city on the Red Sea coast) from September 1997 to July 1999. These machines utilize ct 3:1 gearbox and a hydrodynamic sealing piston pump. These four ESES 2002 wind pumps were tested by pumping from a motionless water depth of 3 m up to an 84 m deep well. A variety of pump diameter sizes varying from 64 to 1400 mm were used. The water pumped was returned to the well after flowing through a settling storage tank having a capacity of 3 m(3). The instrumentation provided a 16 channel data acquisition system to accurately measure the machine performance, including rotor rpm, number of stroke, starting wind speed, Row rate, tail furl angle and other variables. The results verify that the ESES 2002 wind pump is a robust machine as two machines have been running for 2 years continuously without requiring any replacement parts or major or minor maintenance.