Don't they use a standard schrader valve on the top of the shock deelam?
If you mean the allen key bolt at the base of the shock then don't undo it-thats the nitrogen charged chamber and if you open that it'll piss oil all over you and never work very well again! (this is what I remember from the few I serviced 'back in the day', they were the Risse shocked ones if that helps, mark two made by control tech)