Interesting. But all the risers *DO* pop up, no problem at all. The leaks are between the caps and the bodies. I have a hose adapter and have tested every one of these on the driveway: make sure it is throroughly clean - filter and spray head, make sure it is assembled correctly, make sure the wiper seal is seated correctly, put on the cap, make sure it is not misthreaded, make sure cap is tight, and attach the sprinkler to the hose (via adapter). Turn it on and darn, everything is fine except for a nice leak between the cap and the body. Am I missing something? Could it be caused by something other than the wiper seal?
Carol