My floor jack has been acting weird for a while. It acts like it doesn't have any power. It'll go up to whatever I'm trying to lift, but it won't lift it. Which, from what I understand, is what happens when a jack wears out. But the weird part is that it will stay there, without falling down, even if I stand on it. Does anyone know what could cause this. I'm thinking a seal somewhere had a blowout. Also I don't really have any information on it, so I'm not sure if it's worth a rebuild.