<div class="htmlview paragraph">Hydraulic operating pressures on offhighway vehicles have increased steadily over the years. Depending on the function, the majority of the systems now operate between 2250 psi and 3500 psi. External gear pumps have provided the reliability and performance required for most of these applications and with improvements in gear pump technology, they will keep pace with the higher pressure requirements of the earthmoving industry. This paper addresses the development of gear pumps that will meet the future demands of vehicle designers for pumps rated at 4500 psi.</div>