Seat sinks and/or rises on its own
Stool rises to its highest point when there's no weight on it, and/or sinks to the bottom point when weight is on it. It will not hold its height adjustment.
On the top of the cylinder there is a little green button that when pressed releases the cylinder so it can be adjusted up and down. There is a bolt in the underside of the seat in the adjustment mechanism that is keeping the button pressed so it isn't locking into place. To remedy this please follow the steps below.
1. Carefully remove the cylinder from the underside of the seat. When assembled, the cylinder is pressure fit into the adjustment control so it may take some "elbow grease" to remove it from the top.
1.a. To do this, flip the stool upside down and hold the stool off the ground by the cylinder. With a rubber mallet (or a hammer but be sure to protect the metal of the adjustment control) carefully tap around on the underside of the seat. It may take a little time but the top will fall away from the cylinder.
2. Inside the center hole of the adjustment mechanism where the cylinder had been there is a 10mm bolt. With a 10mm socket, turn the bolt CLOCKWISE (half a turn at first) to drive the bolt further into the underside of the seat. This bolt should be out far enough to press the green button when you use the lever to adjust the height, but not so far out that it continually pushes in the green button without using the adjustment lever.
3. Put the cylinder back into the underside of the seat. Test and repeat if necessary.
Please feel free to contact us if the problem persists after troubleshooting.