Many Rainbird sprinkler problems can be solved by removing any dirt or scale buildup, so checking the sprinkler filter for problems in this area is one of the most important steps in troubleshooting. A retaining nut holds the mechanism in place. After removing the nut, check the filter and remove any buildup before replacing it and testing the sprinkler again. Rainbird recommends checking both the stem and the cap.
Most sprinkler systems use gear-drive, rotary sprinkler heads. Rainbird seals the gear drive to protect it from debris. However, a dirty filter reduces pressure, so the drive does not operate correctly. Access to the filter is at the bottom of the sprinkler mechanism. Needle-nosed pliers are useful in removing the filter for inspection and cleaning.
A reduction in water pressure is sometimes due to other problems. If the homeowner has recently planted trees or shrubs in the area, there is a chance that a line has been cut or broken. A wet or muddy area in the lawn around the new planting usually reveals this problem.
New construction in an area also has the potential to increase demands on the pressurized irrigation water and reduce water pressure to individual irrigation lines. Sometimes it is possible to program the system to water the lawn at a time neighbors are not irrigating to improve the water pressure and ensure proper operation of the sprinkler. Reducing the number of sprinkler heads in each zone also increases pressure.