I am using a set of Toro 53380 3/4" in-line valves in a small (100 emitter/6 zone) greenhouse drip irregation system. The controller is a Toro 53768 ECXTRA, which is known good (no voltage to valves when OFF). Neither the master (at 50 PSI city water pressure) or zone valves (at 20 PSI reduced pressure) turn off completely and leak small, but significant amounts of water. I have contacted the TORO help line, but all they could do was tell me to check for dirt, bad parts etc., all of which I had already done. The valves are (apparently) good and the controller is known good - why do the valves not shut off completely? HELP!!!!!