So i blew a tire yesterday. Went and lifted it up and replaced it. I started to lift it back up with the jack to make sure i had it on straight and i hear the air releasing from the rear. So i started it back up and i can hear it trying to put air in but it doesnt go up. I shut the truck off and I could still hear it trying to fill up. Now it sits with a saggy rear. Im sure its something easy as i just saw it raise back up before i lifted it again with the jack but then the air released as i went up. I don't know much about these trucks. I need help!!!