upon taking it apart, I was surprise to find a spring is added to help collapsing the jack. As if the weight of the vehicle is not heavy enough, they install a spring to pull down the jack. After I took out the spring, the jack behave normal. This just shows a terrible design by duralast. I haven't test the strength and qualify of this jack itself. but base on the wrong design, Please do no buy Duralast Hydraulic jack.
Instead, I recommend Arcan XL20 Black Low Profile Steel Service Jack - 2 Ton Capacity