Question
I have an old Toro Custom Eight sprinker control.  It doesn't move through the zones, so I'm considering installilng an electric timer.  Will I have to replace the entire sprinkler system?

Answer
Duff,

No not the entire system.
You have two options. One is to replace the valves to electrics and run wires to them. The other is to buy a Hydraulic conversion module from a TORO dealer. This acts as a electric valve which controls the hydraulic water to the old valves. You will also need to buy an electric controller.
If you can locate your valves I suggest changing them to electric and be done with it. Sooner or later those hyd. valves are going to fail.

Matt