I have an older toro system. When I went to turn the system on for the first time two zones are not working. I think it is the valve. I put one of the known working solenoids on one of the none working zones and it did not work. While the none working zone solenoid worked in a known working zone. It is a screw on type enclosure. The solenoid screwed on top of a base and that base screws off of the entire valve. Inside there is a gasket, spring and a long needle. The top of the needle is white. Would I just need to replace the gasket? What else could it be? Last year this would happen one day and the next day it would suddenly work and I just dealt with it as I just purchased the house but would like to get this fixed before summer hits.
That would be ideal but the location of the valves would make that project a major PITA. Would replacing the valve inside fix this problem? Also what is the part number I need to replace the guts?
If all it took to make a Flo Pro valve reliable was a new diaphragm assembly, then Toro might still be manufacturing them. They are not, and that says plenty.