So i was driving home from work and my f250 started to sputter so i pull over. I get out and check the check valve on the side of the fuel filter and it blows air then i pull the filter and its only got about an inch of fuel at the bottom. I put fuel in the filter and truck started right up and ran for about 30 minutes then died again. A buddy of mine said its the lift pump going out what im wondering is how expensive and how hard is it to change. Any help would be great this is my daily driver and i need it fixed asap.