Why won't my Caterpillar 304C CR prime fuel, and could it be a clogged screen or a bad lift pump?

[Lily Anderson]

I'm having a fuel priming problem on my Caterpillar 304C CR. The machine has been bogging down under load for a while, so I thought it might be a fuel delivery issue. After checking the fuel filter and hand priming it, it won't start at all. I removed the filter and noticed that no fuel comes out when hand priming or turning the key on.

Could this be:

• A clogged fuel screen?
• Bad lift pump?
• Air in the fuel system?

Also, should fuel normally come out of the filter housing during priming? Trying to figure out where to check next before replacing parts.