Simple fuel problem?

[seth]

I bought a non running 300D for $100. I know that it ran ok up until its recent problem. I thought air in the fuel line was the problem because when I pump the bleeder pump with the top of the fuel filter raised a bit a bunch of bubbles would come out. All the fuel hoses were brittle and worn so I assumed thats how the air was getting in. I replaced both filters and all the hoses except for the two coming from the tank. There's no fuel leaking out with a full tank on top of them so I think they're ok (for now). There's no air moving through the lines but there are a few little bubbles that won't go away. That make me think theres no or very low fuel pressure. I can see air in the prefilter also. This is my first time working on a Diesel. I'm thinking fuel pump but I don't even know if diesels have fuel pumps...