Separate from the gear motor assembly, there is a closed loop hydraulic checking device that is powered by the shaft itself. When the panel room divider is traveling in the down position, this hydraulic checking device builds up a certain hydraulic pressure that is dependent on wall travel speed. In normal operation, this pressure is very low and this checking device offers no appreciable braking force on the panel room divider. If, at any time, the panel room divider speed is substantially higher than normal, this checking device offers sufficient braking force to lower the wall at a speed no higher than 150% of normal operating speed.