Remove the cover and put the system into regeneration. pay careful attention when removing the cover, the buttons are a bit fragile on the board and Clack will not warrant broken buttons.
The system "homes" by stalling the motor when the piston reaches its limits. This is a unique design and it is normal to hear the motor get "bogged" down at the end of the piston limits. If the motor stalls or binds in the middle of the stroke, that could indicate a problem with the seal pack/piston. Do not lubricate these items, they are water lubricated. Here is a short tutorial on the valve tear down.