It sounds like the valves are leaking, and not what your thread title states.
You better be drinking more. You purchased Orbit, the cheapest of the cheap, and you are wondering why they are leaking? The way to fix it, is to remove the entire manifold, and replace it with a manifold from Hunter, or Toro, or Rainbird, or K-Rain.
Orbit uses cheap parts made from cheap molds. It is less expensive for my customers to have me pull everything made by Orbit and replace it with professional products, than for me to charge my hourly rate to try hour after hour to try to fix these problems. You might think that they are fixed, then they will leak again.