gear pump cavi ??? well dear all we know that gear pump is a positive desplacement pump which has constant dioscharge at different loads my problem is i need an explaination to this sitiuation " from 1 month at my work i found a breakdown of lubricating pump used to pump oil on a bearing it was a gear pump i found that there is no flow exiting out the pump i checked direction of rotation and pump tempreture i found nothin a friend of mine PRIMED the pump and it has worked i found this strange because of the nature of gear pump after 2 weeks we found that the electric motor of this pump is burned i dont know why ???? after this i changed the gear pump with a larger one which worked without any kind of priming i dont know whats the different or the meaning of this sitiuation pls guys help me ???