I have an 04 Sierra 5.3l, last week I couldn't get her to start so I pulled off a fuel line and bypassed the pump relay to see if I got flow. Pump was humming but no flow. Well, after the pain of dropping the tank and getting the fuel pump assembly apart, I got to the fuel pump intake filter which was clogged badly with what I suspect to be diesel Mixed with water bacteria growth from the local fuel company, that's another story. After calling the dealer to find the part, they said no replacement filter is available so I would have to buy the entire fuel pump assembly, list price @ $400+. Now GM that is just plain assanine and a terrible design flaw. Does anybody sell a replacement filter Aftermarket?