Friend usually the trucks are equipped with a hydraulic clutch, if when you precise the pedel you feel this this does not oppose any resistance, as if it were loose, it would be a problem of a pump or auxiliary cylinder, if not the case, it can happen it is the clutch disc is very spent, but that failure throws another symptoms that is, the skate How to your marches, and it seems to accelerate in neutral, now if you are going to disassemble the clutch I advise you to change the full clutch kit already for safety, it is not appropriate to work in this type of old elements organs with new elements, it will not cost you more, only the replacement. The other possibility is that your thrust bearing is hydraulic but the failure feels like the first one I mention.