Question
I have a irragation pump that was installed 16 yrs ago.  It has worked very well untill this year.  I winterize it every year.  When I set every thing up this yr. one prime and it worked fine for about three weeks.  Then all of a sudden it lost prime and quit.  I checked all the suction conection in fact I have now replased all the suction connections.  The problem is when I prime the pump it starts and well build pressure, I open the valves and it works for about an hour.    Then it appears ro lose prime and quits.  After shuting down the pump I wait about a minute and turn it back on and it starts to build pressure, as soon a I open any valve it seems to draw air from somewhere, although shut down and restart well bring the prime back.  I drawing from a creek with a 2 horse pump suction is 1 1/2" redused to 1 1/4" drawing uphill about 75' and about 15' elevation.

Any help is certainly appreciated.
Thank you
Harland

Answer
Thanks for the question.
Is it possible the screen/ filter is getting partially plugged and causing the problem? That would be my first guess. Creeks tend to have different particles to filter at different times of the year.
Try hooking a hose to the pump and pressurize the whole system. Then carefully check the suction line. The complete pipe, not just the fittings. As I'm sure you know, any leak even a tiny one will affect the pump. Your problem is definitely the suction side of the pump. It's just the process of finding the leak.

Matt