The problem is that the steel rod must slide within the coil for the sensor to work. There is nothing to hold the rod inside the piston, so the entire system depends on gravity to work. The rod stays bottomed in the piston, and as the piston pushes the rod upward, it follows. Gravity must pull the rod back downward as the piston returns. My problem is that I have 2 cylinders mounted sideways, so gravity will not pull the rod back down.