SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

I have Hydro Rain valves installed in my 23 year old residential system, however thanks to PinkFloyd and his picture, I see this valve is exactly the same as the Hardie HR-1.

My problem is this. After 23 years I noted that I was developing dry spots in one(1)of my coverage area, even next to some heads, so I watched and noted the heads on this stage were slow to rise, if at all, and not as forceful as others.

When the stage is called by the controller, the heads (Toro 570 3" popups) only pop up part of the way and gush water (since they do not seal off). If I grab a head or two and pull them all the way up then the other heads will finally seat and all then spray.

If I manually unscrew the knob in the center of the valve itself, all heads immediately popup and seem to spray more forcefully than with the selinoid(sp?).

Now usually when this happens, I replace the selinoid and all is well but not this time. I did replace the selinoid but no improvement. I checked the voltage at the valve box and it reads 26.9 Volts on my meter.

I also note that the problem is worse when my neighbors have there systems going at the same time (lowered water pressure?).

So, does the valve need to be repaired, or replaced? I am very handy but never saw the inside of a valve so dont know what to expect (loose springs shooting out, etc). What part do I replace? Any diagrams out there, or can someone walk me thorough this?

Thanks

Thanks guys for the input. A little surprised by the "replace the valve vs repair the valve" based on the spirited discussions I have seen in here. Since I have 7 others I'm going to try the repair first.

Is that all there is inside the valve is this diaphram? I would think there are springs and check valves/balls etc - which is what I am worried about?

And, in the event that I replace the valve - how do you get a new valve back in place. The valve was screwed into place as pipe was laid. I would have to cut it out and easy to reattach one end with new fitting, but how do I reconnect the other end to the exisiting yet buried pipe??

Ok talked with the parts guy. The ONLY things in there are the diaphragm, and a helper spring that sits on top of the diaphragm and under the bonnet.
So bought the diaphragm, opened up the valve and ta da was exactly as explained.
Took off the bonnet (one note here is that the bonnet contains the bleeder rod - just a small metal rod that is permanently attached to the bottom of the bleeder knob/screw. The rod goes directly down and through the center of the diaphragm and screws into the top of the bonnet). Just pull the bonnet straight up and the bleeder rod comes up with it.
All that is in there is the diaphragm with the spring on top. Remove the spring, remove the diaghragm, replace both back and put on the bonnet (6 screws). Note I cleaned everything in a bucket of water, so I unscrewed the bleeder knob with the bleeder rod from the bonnet to clean. To re-assemble, I found it easier to leave the bleeder knob/rod off the bonnet, install the bonnet, then insert the bleeder knob/rod and screw it tight.

While there were no signs of holes or tears, the new diaphragm did the trick []