jack failed....dented floor
+1...that's exactly what it sounds like. And, sometimes s#!t happens. Rubber mallet will do the trick. Anyone else saying that this guy doesn't know what he's doing, hasn't played around in their garage long enough to know that a hydraulic jack can/will let go at times. That's why you should never be under the car with just a hydraulic jack...you need the jack stand which won't fail.
Ya I use wood to block my car and a jackstand before I get under, better safe than sorry. Honestly it will only take you 2 min extra and you know that you will be safe. Glad he is ok. A dent in the floor is minor in the grand scheme of things.


