Guy's we are having a problem with one of our cond. pmps. When it is starting up whether in auto or man. it just sits there freewheeling for about a minute and then all of a sudden bam off it goes with a slug of water. 0 psi to 220psi just like that. this would be with 1 pmp already running and this 2nd out of 3 pmps starting up. Do you think there is some cavitation going on there? And also can the vent line or seal water line have anything to do with this problem? Any advice will be appreciated. Thanks