I have a six year old irrigation system; one of toro valves is leaking: Model 53682 with flow control, 1" in line valve. I replaced the diaphragm today but it still leaks. There are no pieces of dirt or debris in the valve. The tech at the local irrigation supply store said that the plastic white collar that fits below the diaphragm looks like it might have hairline cracks on it. It does have six uniform length slits on the collar equally spaced around the inner edge but I couldn't see any crack...
