On Mon, 03 Oct 2011 18:28:41 -0400, Rebel1
wrote:

Two of my Hunter PGP 4" sprinkler heads seemed to be working okay based
on the throw of the water. But I noticed both had pools of water around
their bodies, so I assumed there was a leak, perhaps around the cap, and
replaced them.

At one of replaced heads, there was no longer a pool around the body or
in the still-open hole. But the other one leaked a little while the zone
valve was on, but continued to leak much more when the zone valve was off!

There are five heads on this zone. Due to the slope of the lawn, the
leaky head head is downhill from the three that are closest to the
manifold valve, so I figured that maybe gravity was a factor, not that
it really should be. The leaking continued for at least 30 seconds after
the zone valve was off.

One more head, a different model with a fixed 1/4 circle pattern, is at
the bottom of the run. No pooling there.

Is my leaky, new head defective?

Thanks.

R1

If the diaphragm in the control valve is weakening it will cause
leaking at the downhill sprinkler head. In that case it would not stop
completely after a short period. When the valve turns off, listen
closely at the valve for water bypassing the valve.

That was the case for me one time. Repaired the valve and the leaks
stopped.

YMMV