I never have checked that but I can't imagine it not going all the way back in. There is no spring on it, but the clutch fork itself seems to serve as a spring. When the clutch fork returns it pushes the push rod back into the slave cylinder. I have an adjustable nut on a threaded push rod so that I can adjust it outward until it just comes into contact with the clutch fork without applying any pressure. I didn't want the throwout bearing spinning all the time. I think that's how it's supposed to work.