Wilkins 975XL backflow problem

Discussion in 'Irrigation' started by justgeorge, Jul 1, 2006.

  1. justgeorge

    justgeorge LawnSite Senior Member
    Posts: 352

    I've got a customer with a leaking Wilkins 975 XL 3/4" backflow. It is a fairly steady trickle out the dump port on the bottom. I looked at it yesterday (had told him to turn it off at the front-end shut off valve). I turned it back on, and sure enough it's leaking. I turned it off, a bunch of water dumped out all at once, I turned it back on and now no leak. Hooray I fixed it. I ran one zone for a very short period, turn it off, still no leak so I left. This morning the customer called me; his system ran thru the full cycle early this morning, and the steady trickle is back.

    I've searched the web and can't find any 'exploded parts drawings". Any thoughts besides calling a plumber or replacing it?

  2. Midlo Snow Maker

    Midlo Snow Maker LawnSite Member
    Posts: 183

    take it apart and see what is going on
  3. That is a Reduced Pressure Backflow, take the tops off and see if one of the checks has a bad seal or a object is obstructing the seal. I have seen rocks, nuts and solder in the seals.
  4. Also check the dump, more than likely it will be the dump that is not sealing.
    Relief Valve Diaphragm...
  5. aquamtic

    aquamtic LawnSite Senior Member
    Posts: 303

    As londonrain said or a bad #2 Check. It being a 3/4 size, its not worth spending to much time on trying to repair it especially if your not that familiar with an RPZ and cannot test it to be sure that its purpose even works properly. Change out the whole valve
  6. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,310

    Besides the obvious rubber of the diaphragms and seat washers, there is an O-ring that can fail, and its failure will cause that relief valve trickle.
  7. Solder #1 culprit.....
  8. Dirty Water

    Dirty Water LawnSite Fanatic
    Posts: 6,794

    Not here.....

    I see a copper pipe once a year tops.
  9. IN WA:
    Glue #1 culprit....or teflon tape/paste.....or galvanized rust particles...;)
  10. Dirty Water

    Dirty Water LawnSite Fanatic
    Posts: 6,794


    Most of the taps are on domestic poly lines, so it would be teflon tape.

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