How much pressure can I pump into the flat-jack at maximum?
Answer: only 1.2 bar (17 psi) of pressure is needed for the flat-jack to pump her up to the maximum height of 12 cms. This is a quarter of the pressure that is needed for a simple bicycle (which needs 4 to 5 bar of pressure). This is because the flat-jack cushion has a big surface, which makes that only little pressure is needed to lift big weight vehicles like a camper on this big cushion. That is the lovely property of air. With a lot of square cms (like the flat-jack) air lifts gigantic weights of vehicles easily.