SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

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.

If I manually turn the solenoid the system does come on. Not sure if that matters but want to try to give as much information as possible.

After looking at some pictures my valves are toro flo pros. Like the one in the link below. As I said the solenoid works.

http://forums2.gardenweb.com/forums/load/water/msg051940149121.html

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?