[34fordy]

I had an older friend that had an identical jack in his repair shop. It had an automatic safety stop that was spring loaded and as you raised the jack, it would snap into stops for different heights. If you raised to the desired height and did not lower to the last stop you could get a "surprise". This particular jack would leak a little air and there would be a sudden drop to the last safety stop. A young friend of mine had raised the jack quite high without letting the jack relax to the stop. An older experienced mechanic was underneath when the car dropped a couple inches to the last stop. It made a bang and I have never seen anyone get out from underneath a car that fast. Needless to say he heard a few choice words!