First of all I only do lawn maintenance and don't know anything about irrigation. I do not plan on doing any repairs, I would just like to be able to give my customer an intelligent answer as to what is wrong and help them find a company to repair the problem if it's not repaired by my next visit. During my last visit in the fall I noticed the leak and notified the customer that it needed to be repaired. Well I show up last month for a spring clean-up and it is still not repaired. He told me he had been trying to get the original installer to look at it, however a month later still no fix. The leaking head is the second highest head on the lawn and is approximately 6-8 feet higher and about 60' from the 3 valve manifold. From what I understand the line should have no pressure until the valve opens for the particular zone (I could be wrong). The manifold box does not have a shut off valve that I can find. There are two green 8" covers near the main water valve, one that contains nothing and one with a ball valve. I shut off the ball valve and left it off for about 45 mins while I finished my lawn work and came back and it was still leaking at the same rate. It appears it is leaking directly from the top of the head around a small 3/8" brown cover with one screw. I would think with it being one of the highest heads the water would drain back down when no pressure is in the line. Any idea what the problem could be? Bad head, bad valve? Any help would be appreciated.