Sorry for the delay. We are always glad to help over the phone, and sometimes it is easier. Also sorry for your problem. We will help any way we can. Sounds like you have had good service from your CSV3B valve as it has worked well for 15 years or so. Many times they can be repaired, but a complete replacement is not expensive either. The new CSV3A has been improved over the CSV3B. Most last longer than 15 years, but wear from sediment when pumping from lakes, ponds, and sandy wells will shorten their life. Swap where the two hoses are attached. If the valve shuts down and gives almost no flow or pressure, the the regulator is the problem. If after switching the hoses the pump still cycles off when using water the big part of the valve is the problem.
