Question
Hi Jeff,
I have 3 weeping sprinkler heads on two different anti siphon valves. I have rebuilt on of Champion brass valves with a Champion rebuilt kit. I rebuilt them because they were leaking. They still leak, the other has a new diaphram side (the entire assembly is new). The leakers are the lowest ones in the lawn. I was thinking they leaked because I have them adjusted to allow too much flow, but cannot figure it out. I have disassembled them a few time to insure they were built correctly, to no avail, the leaking is just making muddy pools in my yard. help please if you can.

Naomi

Answer
Water seeping out of sprinklers has two main causes.  The most common is that the control valve is leaking, allowing water to pass through.  The other cause is low head drainage, meaning that the sprinklers that have the lowest elevation tend to let the water that remains in the lines drain out of them.  You have already rebuilt the valve, but it could be that it is worn or warped or has some other defect that makes it leak.   You may want to just replace the valves with new.  You can also try replacing the sprinklers with heads that have internal check valves that keep water from seeping out of them.  This will not work very well though if the valves are leaking a lot.