Festo valve.... why wont it work?
 

How do you connect up the Festo sylenoid? There are two + or - 12V wires, and a ground wire, but any combination i hook up to my relay wont work correctly. How do I hook it up to a relay (digital)?

You hook up the ground to the ground of the robot, not to the relay, then you put the two wires on the relay, which one doesn't really matter, when you push the button to activate it, you'll have to hold it down, unless you alter the programming to make it like a double solenoid works. If that isn't working maybe you put it together wrong, search the forums and you'll find a link to the pdf of how to put it together

a matter of fact I have it on my server Festo Valve Assembly

The solenoids also need a minimum pressure in order to activate. Are you running the solenoid in a fully (or mostly) charged system?

Also, does it activate when you press the manual button on it?

DO NOT GROUND IT!!!! It does not reverse, it is only on or off so you only need the 2 pins that are | | not the _ one , one of the | are + and the other -, this is what that led gasket was for