Open cycle on atc sluggish

As the title stated, my atc is experiencing a problem that just now popped up.

When activating the open cycle of the gripper, it takes now almost three seconds
and sometimes I even have to lightly rap the tool holder with a small plastic hammer.

I have visually watched the opening cycle and it appears that the gripper is either
not getting enough pressure from the air pot and or getting it quickly enough,
or there is something dragging inside that is keeping it from opening smoothly!

This is a 10 hp ATC Colombo spindle. The spindle has not been crashed but it has sat
idle for three years and we do have a lot of humidity here!

Any suggestions?

Mike

Do you have water in your air lines? You really need clean, dry air.

Ger I would say that might be it, but I haven't made over maybe 10-12 air hook ups for testing this. I do not have a dryer on my air system yet but I didn't think a few short tests would give enough time for the air to affect the system that quickly! Yep, I assumed!

Is there anything I can do short of pulling the spindle and shipping it off for cleaning?

Would it be the air pot or the belleville washer stack that would be giving the problem?

Thank you for your input!

Mike