cat 40 tool clamping problem

[longcut]

I have a sharp 2412 vertical machining center (10 pos tool changer) and it has developed a problem clamping the tool.
It appears the cylinder/actuator is not letting the collet fingers come down far enough to grab or release the tool.
Air pressure is fine and I pulled the hose from top of cyclinder and there appears to be sufficient pressure. Any ideas???? Thanks, Matt

[bborb]

Symptoms can be deceiving such as a bent finger, taper lock........... usually the stroke is adjustable and is set at the factory and RARELY changes. Many machine tools have tool "kickout" where the drawbar ass'y strokes far enough to hit the top of the retention knob of the toolholder and push it .05" downward.
Look up in the spindle for damaged fingers. Change tools by hand, paying attention to the tool release and see if it pushes the tool down into your hand at least 1/32"

[Mitsui Seiki]

I don't know how it works on a Sharp but a Mitsui Seiki has spring washers.
If some of them are broke ,the open/close mechanism doesn't work as it should.