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

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.

I have a 7-zone system that was installed in (I think) the late 90's and
it has these Hunter PGP springlers.

http://www.sprinkler.com/skin/fronte...gpcrosscut.jpg
http://www.mapletrade.co.nz/Images/Irrigation/pgp.jpg

Two sizes, but mostly large (not 4" diameter, but maybe 4" pop-up).
I've been replacing many of them over the past few years - primarily
because they get stuck at one end of their rotation pattern and just sit
there and click unless I give them a tweak by hand and then they'll make
one sweep and come back to the same position and sit there.

Has anyone ever taken these apart to see if any gears can be cleaned or
fixed?

The other reason I've replaced some of them because they seem to leak
around the joint where the sprinker retaining collar gets screwed into
the base canister. I can't figure out why it leaks (it seems clean) but
I also notice that new units (like these old ones) don't seem to have a
gasket where the collar meets the canister.

At one of replaced heads, there was no longer a pool around the body
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!

the leaky head head is downhill so I figured that maybe gravity was
a factor, not that it really should be.

Well, yes. These are self-draining sprinklers. I think when the
pressure is turned off and they re-seat themselves back down into their
canisters (because of the big spring they have) it must open or expose
some passage where water can passively drain from them.

Is my leaky, new head defective?

Unless you cracked the elbow or the extension where the canister is
screwed into, I'd say no.

Be aware that the extension tubes are very soft plastic (at least the
black plastic multi-segmented ones sold by home despot).

I was done messing around with these things about a month ago. Some
still need tweaking, but I'll do that next summer.

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?

I don't know your specific haeds, but popup sprinklers do tend to leak around
the popup part when the pressure is too low to get a tight seal.. So, when the
water is turned off, water will come out of the lowest head until the level
inside the pipe has dropped below the head. Sometimes, the water will leak
around the popup under pressure due to dirt in the sliding part keeping it from
sealing. Pushing the head down a few times while it is working may clean out the
dirt so it seals properly.

Thanks for the feedback, Home Guy and Bob. Tomorrow, I'll be better
educated when I go back to the place I bought the heads, a professional
sprinkler company, not HD or Lowes, and describe the problem.

On Oct 3, 8:59*pm, Rebel1 wrote:
Thanks for the feedback, Home Guy and Bob. Tomorrow, I'll be better
educated when I go back to the place I bought the heads, a professional
sprinkler company, not HD or Lowes, and describe the problem.

What problem? It's normal for popup heads to leak
slighltly around the seal between the popup part and
the base when it's watering. They tend to leak more
with age. You just don't want a lot
of water spewing out. It's also perfectly normal for
water to come out of the head for 30 secs after it's
shut off, if it's a downhill run. Why would you care
about water trickling for 30 secs into the lawn?

On Oct 3, 8:59*pm, Rebel1 wrote:
Thanks for the feedback, Home Guy and Bob. Tomorrow, I'll be better
educated when I go back to the place I bought the heads, a professional
sprinkler company, not HD or Lowes, and describe the problem.

I've taken mine apart to clean them and I don't see anything in them
that would "turn off" the water at the head. I would expect a low one
to drain the from the higher ones.

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

On 10/4/2011 1:17 PM, Oren wrote:
On Mon, 03 Oct 2011 18:28:41 -0400,
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

You could have also watched your water meter to see if any of the dials
was spinning, which would indicate water flow. But on my setup there is
also a master valve in the line that feeds the manifold, so it too would
also have to leak before showing up on the meter.

I would have a major problem if it was something wrong in the zone
valve, as Hardie replacement parts are very hard to find. So I couldn't
take a shortcut and buy a whole new valve and swap the new diaphragm,
relay, etc. with the parts in the old body.

Anyway, I went back to the place I bought the new heads. He gave me a
replacement filter screen that goes inside the housing, where the water
enters. It had a big rubber washer on it that presses against the
housing and prevents water inflow when the zone valve is closed. Problem
solved. It a standard part in the Hunter stainless steel model.

On Fri, 07 Oct 2011 16:37:56 -0400, Rebel1
wrote:

On 10/4/2011 1:17 PM, Oren wrote:
On Mon, 03 Oct 2011 18:28:41 -0400,
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

You could have also watched your water meter to see if any of the dials
was spinning, which would indicate water flow. But on my setup there is
also a master valve in the line that feeds the manifold, so it too would
also have to leak before showing up on the meter.

I would have a major problem if it was something wrong in the zone
valve, as Hardie replacement parts are very hard to find. So I couldn't
take a shortcut and buy a whole new valve and swap the new diaphragm,
relay, etc. with the parts in the old body.

Anyway, I went back to the place I bought the new heads. He gave me a
replacement filter screen that goes inside the housing, where the water
enters. It had a big rubber washer on it that presses against the
housing and prevents water inflow when the zone valve is closed. Problem
solved. It a standard part in the Hunter stainless steel model.


Good point about the spinning meter dial. In my case I could hear the
water flowing past the valve.

Glad you got things fixed.

Rebel1 wrote:

I went back to the place I bought the new heads. He gave me a
replacement filter screen that goes inside the housing, where the
water enters. It had a big rubber washer on it that presses against
the housing and prevents water inflow when the zone valve is closed.

Problem solved. It a standard part in the Hunter stainless steel
model.

I don't get it.

If the zone valve is closed, then a small amount of dribbling water
shouldn't be causing you grief, and it wouldn't worth my time to shlep
across town and get this part and dig down in the dirt to install it.

If your zone valve is leaking, then I'm sorry but this ain't gonna fix
it.

If it gets down to freezing in your area in the winter, then you're
gonna wish you hadn't installed that rubber thing.