I have an older Rain Bird irrigation system with above-ground "jar-head" Richdel 1" valves. One of the valves only works when I open it slightly or loosen the bleed screw. When I do so it leaks water, but I get good pressure. I replaced the diaphram in that valve. Seemed to work for a while, then it went back to the open valve or bleed screw scenario. I am running the other three valves closed. They are functioning, but leaking when opened. Are there O rings and seals that should be replaced in these valves that might solve my problem? Any advice would be greatly appreciated. Thanks.