My irrigation pump keeps losing its prime. How do I check for leaks in the suction line?

My irrigation pump keeps losing its prime. How do I check for leaks in the suction line?
Hey Don,
Before I went through the hassle of pulling the suction line and checking for leaks I would go for the most likely suppect. The check valve. If the check valve were faulty or had a piece of crud caught in there so it doesn't close completely you would lose prime every time the pump shut off. Good luck, Tom