1100 not releasing tool from spindle

We have an 1100 mill with a power drawbar that is not releasing the tool from the spindle when actuated. The cylinder appears to be fully engaging the top of the drawbar. I have not tried to loosen the nut on top to give it more travel - I wasn’t sure if I could that with the tool clamped up. There is sufficient air- 100psi.

Any suggestions?

What 1100 series is this? PCNC, M, MX? If it happens to be an MX, and you see that your spring stack on your drawbar is compressing, try giving the side of the tool holder a few tap with a dead blow hammer. I have seen grippers stick before.

Thanks. We got it this morning. It is a MX. We bumped the pressure from 100 to 110-115, checked the stroke which was OK, and got it out eventually. We checked the BT30 gripper and cleaned and lubed and it appears to be working OK now. Thanks for the response.

Just for the record, after you have set the 110-115 PSI you can still have problems with tooling not releasing from spindle, I have found that sometimes the FLAT SCREW at power drawbar bottom (the one next to Shoulder screw) come loose. If you tighten again, the tool will realse fine from spindle.