Steam Version
DF Hack Steam Version

Pump stack builds just fine during gameplay. After the game autosaves, stack breaks most of the pumps but not all. Same behavior after loading the save on the first tick. Pump stack is supported on top and bottom. Only disconnected gear is several gears separated from the pumps. It also breaks a set number of pumps away from the top though they both break all the way to the bottom except the last pumps which don't have power holes.