Is your problem the clicker not staying extended when you operate the plunger or if it stays exyended not retracting whwn toy opertate the plunger. This is the most common failure with the 3 piece mechanisms and I have only ever seen 2 causes: 1) the refill spring hanging up because it is on the refill tip backwards - the fix is the larger diameter end of the spring goes toward the tip. 2) the More common one is the white plastic sleeve turning within the within the clip assembly. The clip mechanism works by the internal part rotating a partial turn each time the button is depressed while the sleeve remains fixed this allows it to lock on one depression and remain extended and unlock on the next depression allowing the the refill to retract. If the sleeve slips it does not work. The best approach I've found is to assemble the click mechanism into the clip assembly applying a little blue loctite to the sleeve before pressing the clip assembly in place this will assure that the sleeve stays fixed and the click will work. That is a very reliable click mechanism and it will probably never wear out in a normal lifetime.
